Unraveling the Parablechnum cordatum (Blechnaceae: Polypodiopsida) complex puzzle

Abstract

Parablechnum cordatum (Blechnaceae) exhibits significant morphological variability, with many species considered as its synonyms, and is treated as a species complex by several authors. In this study, we offer a comprehensive revision of the taxon and an updated circumscription of Parablechnum usterianum, a species frequently confused with P. cordatum, leading to a refined understanding of species delimitation. Our analysis, based on morphological and spore micro- and ultrastructural examination of Brazilian specimens within the complex, recognizes three distinct species: Parablechnum cordatum s.s., Parablechnum brasiliense, and Parablechnum regnellianum, the latter being treated as a synonym but now resurrected with a new combination. Here, we present a key to the species, along with detailed descriptions, diagnostic images, distribution maps, lectotypifications, synonymies, and nomenclatural clarifications.

Keywords: ferns; systematics; species complex; spores; taxonomy

Introduction

Blechnaceae is a sub-cosmopolitan family of leptosporangiate ferns with its center of diversity situated in the Southern Hemisphere. The family comprises 25 accepted genera and three subfamilies (Gasper et al., 2016; Molino et al., 2019). Parablechnum C.Presl stands out as the largest genus, consisting of ca. 65 species with a pantropical distribution (Gasper et al., 2017). The distinctive morphological features of this genus include truncate and 1-pinnate, petiolulate blades. Additionally, in most species, large scales are located at the base of the petiole, and numerous scales are distributed on rachises, costae, costulae, veins, and even blades themselves, with mostly species with dimorphic fronds (Gasper et al., 2017; Dittrich et al., 2018).

While Parablechnum is well-defined as a monophyletic genus, P. cordatum remains poorly delimited, being recognized as a species complex by several authors due to its significant morphological variation, wide geographic distribution, and high number of synonyms (Tryon & Tryon, 1982; Tryon & Stolze, 1993; Smith, 1995; Prada et al., 2008; Smith and Kessler 2018; Wal et al., 2021). The defining features of the complex include sterile pinnae that are initially free, and petiolulate at the base of the frond but becoming sessile, and adnate towards the apex. Additionally, numerous scales are present in the rhizome, petiole, rachis, and veins (Dittrich, 2005; Vicent, 2017).

The presence of various intermediary forms among the P. cordatum complex species difficults its proper delimitation. As these species are cryptic (i.e., possessing traits or features that make them difficult to detect, identify, or differentiate from other species within their taxonomic group), they were previously synonymized to avoid misidentification (Kazmirczak, 1999). The synonymization includes Blechnum simile Sehnem, Blechnum raddianum Rosenst. (= Parablechnum brasiliense (Raddi) M.T.Medeiros & Schwartsb.), Blechnum regnellianum (Kunze) C.Chr, Blechnum macahense Brade, and Blechnum itatiaiense Brade. Consequently, there is a need for clarity within this species complex to enhance identification accuracy.

Ongoing discussions exist regarding the similarities between P. cordatum s.s. and other species sharing similar morphologies, such as Parablechnum chilense (Kaulf.) Gasper & Salino, Parablechnum schiedeanum (Schltdl. ex C.Presl) Gasper & Salino, Parablechnum falciforme (Liebm.) Gasper & Salino, and Parablechnum varians (C.Chr.) A.Wal, S.Molino & Gabriel y Galán, which are currently recognized as legitimate taxa (Moran, 1995; Mickel & Smith, 2004; Rolleri & Prada, 2006; Rodríguez, 2015; Vicent, 2017; Wal et al., 2021). However, it is important to note that these species are not present in Brazil and therefore are not treated in this work. Hereafter, any reference made to the P. cordatum complex will encompass the P. cordatum species and the additional taxa classified as its synonyms.

Within ferns, cryptic species are a common occurrence, especially the ones with widespread distribution (Paris et al., 1989; Masuyama et al., 2002; Yatabe et al., 2009; Fayle et al., 2010). In cases where species are difficult to identify due to their morphological similarity, the analysis of microscopic characters might be a way to circumvent this issue (Schuettpelz et al., 2018). In ferns, a microcharacter widely used and analyzed in taxonomy are spores since they aid in distinguishing very similar taxa and solving some species complexes (e.g., Dyer et al. ,2012; Wei & Dong, 2012; Molino et al., 2020; Shah et al., 2020; Martínez-Becerril et al., 2021).

The study of spores in Blechnaceae began with Erdtman (1957), and since then it has been a widely used tool in several studies of the family (e.g., Morbelli, 1976; Tryon & Lugardon, 1991; Ramos Giacosa et al., 2009; Passarelli et al., 2010; Moran et al., 2018) proving to be an important character in delimiting subfamilies, genera, and species (Moran et al., 2018; Ramos Giacosa ,2019; Molino et al., 2020; Silva et al., 2021). In the P. cordatum complex, aside from external morphology, variations in spore characteristics are evident. Different studies that analyzed spores from specimens identified as P. cordatum have revealed significant disparities in their results, suggesting that the complex indeed comprises distinct species (for examples, see Ramos Giacosa et al., 2009; Moran et al., 2018; Silva et al., 2019; Wal et al., 2021).

The differences in the external morphology of the plants within the complex, along with the morphology of their spores and the analysis of type materials, supported our hypothesis that the taxon Parablechnum cordatum comprises multiple species, and upholds the separation suggested by previous authors. Therefore, we present a comprehensive taxonomic review of P. cordatum complex species found in Brazil, to clarify and delimit the constituent taxa within this complex, elucidate the distinguishing features between these taxa, and resurrect the names of species currently treated as synonyms.

Material And Methods

Material acquisition and processing

Aiming to encompass most of the morphological plasticity observed within the P. cordatum complex, we analyzed 301 specimens (physical and virtual exsiccates) based on the following herbaria: ALCB, B, BHCB, BM, COR, CRI, F, FLOR, FURB, HB, HRCB, HSTM, IAN, K, L, MBM, MBML, NY, P, PI, R, RB, SJRP, UB, UCS, UEC, UFG, UNIP, UPCB, US, and VIES (herbaria abbreviations follows Thiers, 2022). We included specimens of Parablechnum usterianum (Christ) Gasper & Salino, a species often confused with P. cordatum. We analyzed virtual exsiccates using online herbaria available at Jabot (2022), speciesLink (2022), and Reflora (2022). All analyzed specimens are described in the section Taxonomic Treatment (types being identified with an exclamation mark).

Following, we analyzed the type specimens of P. cordatum and P. usterianum and the type specimens of species treated as synonyms, namely: Blechnum simile, B. raddianum (= Parablechnum brasilisense), B. regnellianum, B. macahense, and B. itatiaiense. We performed the analysis of the type specimens online through high-resolution images. We analyzed the spores’ ultrastructures using fertile pinna that were previously donated.

We analyzed the specimens with a dissecting microscope (model Stemi DV4, Zeiss) and made measurements using a ruler and caliper. We performed image analyses using ImageJ (Abramoff et al., 2004). The descriptive terms followed Lellinger et al. (2002), and we elaborated a dichotomous key containing the morphotypes identified within the P. cordatum complex. Finally, we prepared distribution maps using georeferenced data from each analyzed specimen (Machado & Gasper, 2024). We mapped species distribution concerning biomes and ecoregions (Dinerstein et al., 2017) using QGIS 3.16 (2022).

Micro- and ultrastructure of spores

We carried out spore microstructure analysis for 38 individuals using light microscopy (LM) (Machado & Gasper, 2024) attempting to encompass the morphological plasticity observed in the previous analysis. We acetolyzed the spores according to the method described by Erdtman (1960), a standard procedure for spore analysis in OM (Halbritter et al., 2018). The acetolysis method consists of heating the spores in a solution of sulfuric acid and acetic anhydride to break down all substances not formed by sporopollenin (Halbritter et al., 2018). Afterward, the spores are centrifuged in distilled water and transferred to slides with glycerin for further analysis. Analysis of spores in LM was performed using a Zeiss Axiostar Plus microscope. For each individual, we captured images of at least 30 spores in equatorial view and made measurements of polar diameter (the minor diameter from the spore, that corresponds to the height) and equatorial diameter (the major diameter, which corresponds to the width). These measurements excluded the perine (i.e., the spore’s outer layer). For the same spores, we measured the extent of the cristae thickness, considering the base of the perine as the starting point of the cristae.

For the analysis of spores’ ultrastructure, we analyzed 39 individuals. A piece of fertile pinna was scraped off over stubs covered with adhesive carbon tape which were then coated with a layer of pure gold in a Quorum Q150R ES magnetron sputtering machine for approximately three minutes. Subsequently, we analyzed the stubs and obtained digital images using a Tescan VEGA3 scanning electron microscope. We described the spore ornamentation using the terminology proposed by Punt et al. (2007).

Statistical analysis

We obtained mean spores’ polar diameter, equatorial diameter, and cristae thickness from spores for each individual analyzed in LM. Based on the data obtained with spores and morphological analysis, we were able to divide the complex into species for statistical analysis. To test if spores’ measurements changed between species, we performed a Kruskal-Wallis test since regression residuals were non-normally distributed (indicated by the Shapiro-Wilk test). We made pairwise comparisons between each species via Dunn’s test with a Bonferroni correction at a significance level of p < 0.05. To know how notable the differences in the variables among species were, we calculated the eta-squared effect size (η²). We performed the analyses using the rstatix R package (Kassambara, 2021; R Core Team, 2022) and generated graphics via the ggpubr package (Kassambara & Kassambara, 2020).

Results

We were able to segregate the P. cordatum complex into three species: P. cordatum itself (Fig. 1), Parablechnum regnellianum (comb. nov. for B. regnellianum, Fig. 2), and Parablechnum brasiliense (Fig. 3), besides P. usterianum (Fig. 4).

Figure 1.
Parablechnum cordatum. A. Scanning Electron Microscopy of a spore (A. Korte 5908, FURB). B. Spore under Light Microscopy (A. L. Gasper 572, FURB). C, D. Rhizome, and scales of rhizomes’ apex, respectively (P. Schwirkowski 1152, FURB). E. Pinna apex form (A. Korte 4532, FURB). F, G. Detail of pinna apex margin (A. Korte 4532, FURB). Scale bars = 20 µm (A, B), 1 cm (C), 0.5 cm (D, E, F, G).

Figure 2.
Parablechnum regnellianum. A. Scanning Electron Microscopy of a spore (L. T. D. Dombrowski 13066, MBM). B. Spore under Light Microscopy (O. S. Ribas 3614, MBM). C, D. Rhizome, and scales of rhizomes’ apex, respectively (N. P. Smith 648, FURB). E, F. Pinna apex form, and detail of pinna apex margin, respectively (G. G. Hatschbach 10793, MBM). G, H. Pinna apex form, and detail of pinna apex margin, respectively (P. Campos Porto 3078, RB). The arrow points to the stolon (C). Scale bars = 20 µm (A, B), 1 cm (C), 0.5 cm (D, E, F, G, H).

Figure 3.
Parablechnum brasiliense. A. Scanning Electron Microscopy of a spore (R. A. Engelmann 243, RB). B. Spore under Light Microscopy (A. Kassner-Filho 2599, FURB). C, D. Rhizome, and scales of rhizomes’ apex, respectively (A. Santos 234, RB). E, F. Pinna apex form, and detail of pinna apex margin, respectively (P. H. Labiak 51, UPCB). G, H. Pinna apex form, and detail of pinna apex margin, respectively (Brade 17969, RB). Scale bars = 20 µm (A, B), 1 cm (C), 0.5 cm (D, E, F, G, H).

Figure 4.
Parablechnum usterianum. A. Scanning Electron Microscopy of a spore (A. Kassner-Filho 3031, FURB). B. Rhizome (A. Kassner-Filho 3031, FURB). C. Spore under Light Microscopy (F. Gonzatti 895, UCS). D. Scales of rhizomes’ apex (A. Kassner-Filho 3031, FURB). E, F. Pinna apex form, and detail of pinna apex margin, respectively (L. A. Funez 7122, FURB). Scale bars = 20 µm (A, C), 1 cm (B), 0.5 cm (D, E, F).

The morphological characters used to distinguish the species of the complex are the pinnae apex form, pinnae length, and pinnae margins. Regarding the pinnae apex (Fig. 5), both P. brasiliense and P. cordatum have an attenuate apex with elongated extensions that taper narrowly (Figs. 5A-C). However, in P. brasiliense, the pinnae may also exhibit an acuminate apex, which also forms elongated extensions, but with wider angles. Parablechnum regnellianum can present pinnae with acute apex or round apex (Figs. 5D-E). In some cases, within the same individuals exhibiting an acute apex, P. regnellianum can present a slightly acuminate apex, forming tiny extensions. Parablechnum usterianum distinguishes itself from the other species by presenting a cuneate apex (Fig. 5 F , Tab. 2).

Figure 5.
Comparison of the pinnae apex of the species, which is acuminate (A) or attenuate (B) in Parablechnum brasiliense (Brade 17969, RB), attenuate (C) in Parablechnum cordatum (A. Korte 4532, FURB), round (D) or acute (E) in Parablechnum regnellianum (P. Campos Porto 3078, RB), and cuneate (F) in Parablechnum usterianum (L. A. Funez 7122, FURB). It is possible to observe the apex margins, which are serrate (with teeth acroscopically oriented, directed towards the apex) in A-C, and dentate (with teeth oriented outward from the margin, directed away from the margin, not acroscopically) in D-F. Scale bar = 1 cm.

Parablechnum cordatum, P. brasiliense, and P. regnellianum have a similar distribution from the southern region of Brazil to Colombia (Fig. 6). The most frequent and widely distributed species is P. cordatum. In contrast, P. usterianum is the only species that has been recorded only for Brazil. Ecoregions are detailed in Tab. 1.

Figure 6.
Distribution maps of the species. Different colors indicate different biomes where a species can occur, according to Dinerstein et al. (2017). Mangroves were removed from the maps for a matter of scale but this can be seen in Table 1. Montane Grasslands and Shrublands and Tropical and Subtropical Dry Broadleaf Forests appear in small areas on the P. brasiliense and P. cordatum distribution maps, respectively.

Table 1.
Species occurrences regarding biomes and ecoregions, following (Dinerstein et al., 2017). P. cord = Parablechnum cordatum; P. bras = Parablechnum brasiliense; P. regn = Parablechnum regnellianum; P. uste = Parablechnum usterianum.

Biome	Species
Ecoregion	P. cord	P. bras	P. regn	P. uste
Mangroves
Southern Atlantic Brazilian mangroves	X
Montane Grasslands and Shrublands
Northern Andean páramo		X
Tropical and Subtropical Dry Broadleaf Forests
Cauca Valley dry forests	X
Magdalena Valley dry forests	X
Tropical and Subtropical Grasslands, Savannas and Shrublands
Campos Rupestres montane savanna	X	X	X	X
Cerrado	X	X	X	X
Humid Chaco			X
Uruguayan savanna			X	X
Tropical and Subtropical Moist Broadleaf Forests
Alto Paraná Atlantic forests	X	X	X
Araucaria moist forests	X	X	X	X
Atlantic Coast restingas				X
Bahia coastal forests	X	X	X
Bahia interior forests	X	X	X
Bolivian Yungas	X
Eastern Cordillera Real montane forests	X
Magdalena Valley montane forests	X	X	X
Marañón dry forests	X
Napo moist forests		X
Northwest Andean montane forests	X
Peruvian Yungas	X
Serra do Mar coastal forests	X	X	X	X
Southern Andean Yungas			X
Southwest Amazon moist forests	X
Ucayali moist forests		X

Table 2.
Diagnostic characteristics for the species analyzed regarding spores and pinnae.

		P. cordatum	P. brasiliense	P. regnellianum	P. usterianum
Spores	Cristae tdickness (µm)	Large (7 to 13)	Medium-Large (6 to 10)	Small (2 to 5.5 µm)	Small (3 to 6)
	Areolae size (µm)	Large (>30)	Small-Large (5 to 30)	Small (5 to 15)	Small-Large (5 to 30)
	Density of Filaments	Rare or absent	Numerous	Numerous	Numerous
Pinnae	Apex form	Attenuate	Attenuate-acuminate	Acute to round, sometimes forming a discreet attenuate apex	Cuneate
	Apex margin	Serrate	Serrate	Dentate	Dentate
	Length (cm)	9-24	4-15	3-12	9-18

Regarding the pinnae length, Parablechnum cordatum presents the largest pinnae, while P. brasiliense and P. regnellianum exhibit the smaller pinnae length within the complex. As for the margin’s ornamentation of the pinnae, P. brasiliense and P. cordatum possess serrate margins with teeth acroscopically oriented (directed towards the apex) (Figs. 1F-G, 3F, 3H, 5A-C), while P. usterianum and P. regnellianum possess dentate margins with teeth oriented outward from the margin (directed away from the margin, not acroscopically) (Figs. 2F, 2H, 4F, 5D-F, Tab. 2).

Spores’ equatorial and polar diameters were not significantly different among species (Kruskal-Wallis η² = 0.0161 and 0.0187, respectively, Tab. 3), presenting similar sizes for both measurements (values of equatorial and polar diameter, respectively: P. regnellianum 49.63 ± 11.48 µm and 50.01 ± 10.87 µm; P. brasiliense 50.06 ± 11.03 µm and 50.04 ± 10.56 µm; P. cordatum 53.76 ± 10.93 µm and 52.73 ± 10.28 µm; P. usterianum 45.81 ± 9.38 µm and 45.06 ± 9.42 µm). Despite that, the cristae thickness proved to be a good character to distinguish all the species (η² = 0.592), with an exception for the distinction between P. regnellianum versus P. usterianum, and P. brasiliense versus P. cordatum (Fig. 7, Tab. 3).

Figure 7.
Boxplots showing the variation of cristae thickness (µm) among four species of Parablechnum analyzed in this study. The thick lines inside the boxes correspond to the median, and the lower and upper boundaries of the boxes correspond with the first (25^th) and third percentile (75^th), respectively. Lower and upper whiskers indicate the minimum and maximum values of cristae thickness, respectively, and extend 1.5 times the interquartile range. Colored dots above the whiskers indicate outliers. Each bracket above the boxes indicates a comparison between species (* = p < 0.0001).

Table 3.
Values of Kruskal-Wallis test for differences among the spores’ measurements (polar diameter, equatorial (=Equat.) diameter and cristae thickness) and the species analyzed. Group 1 and Group 2 correspond to the compared species in the pairwise test. Z statistic = Test statistic (z-value) used to compute the p-value; p.adj = the adjusted p-value based on Bonferroni correction. Values are given in µm.

Species		Polar diameter		Equat. diameter		Cristae thickness
Group 1	Group2	z-statistic	p.adj	z-statistic	p.adj	z-statistic	p.adj
P. regnellianum	P. brasiliense	0.59	1.000	0.13	1.000	19.78	0.000
P. regnellianum	P. cordatum	3.24	0.007	2.36	0.109	19.25	0.000
P. regnellianum	P. usterianum	-3.06	0.013	-4.05	0.000	2.58	0.060
P. brasiliense	P. cordatum	2.86	0.026	2.31	0.126	5.81	0.000
P. brasiliense	P. usterianum	-3.59	0.002	-4.24	0.000	-12.69	0.000
P. cordatum	P. usterianum	-5.35	0.000	-5.42	0.000	-14.81	0.000

Scanning electron microscopy (SEM) analysis revealed that the species can be separated regarding the abundance of filaments and areolae sizes. These filaments are difficult to observe in LM, and thus SEM is the best method to observe them. Parablechnum species analyzed were segregated into two groups according to the abundance of filaments. The first group is characterized by P. cordatum, with few or no filaments (Fig. 1 A ), big cristae (10.17 ± 2.43 µm, Fig. 1 B ), and big areolae measuring at least 30 µm long. The second group, formed by P. regnellianum, P. brasiliense, and P. usterianum, is characterized by numerous filaments (Figs. 2A, 3A, 4A, respectively). Despite their filaments being similar in quantity, these species vary in cristae thickness and areolae size. In P. regnellianum, the areolae are small (5 to 15 µm long), and so are their cristae (4.06 ± 1.26 µm, Fig. 2 B ). Parablechnum usterianum and P. brasiliense have large or small areolae, but their cristae differ in thickness. While in P. usterianum the cristae are small (4.52 ± 1.31 µm, Fig. 4 C ), in P. brasiliense the cristae are medium to large (7.6 ± 2.26, Fig. 3 B , Tab. 3). The spores of the type specimen analyzed under SEM and their respective exsiccates can be seen in ^{Figs. S1}, ^S2, and ^S3.

Key to Parablechnum cordatum Complex Species

1a. Pinnae evidently revolute, with cuneate apexParablechnum usterianum

1b. Pinnae slightly revolute to plane, with acute, attenuate, or acuminate apex 2

2a. Pinnae with acute or slightly acuminate apex (forming tiny extensions); margin of the pinnae apex dentate, with teeth oriented outwards from the marginsParablechnum regnellianum

2b. Pinnae with slightly to strongly acuminate or attenuate apex, potentially forming large extensions; margin of the pinnae apex serrate, with teeth acroscopically oriented from the margin 3

3a. Pinnae apex with large extensions or not; sterile pinnae 4-15 cm long; spores with many filamentsParablechnum brasiliense

3b. Pinnae apex always with large extensions; sterile pinnae 10-29 cm long; spores with few or no filaments at allParablechnum cordatum

Taxonomic Treatment

Parablechnum brasiliense (Raddi) M.T.Medeiros & Schwartsb. Hoehnea 50(e422022): 10. 2023.

Lomaria brasiliensis Raddi, Syn. Fil. Bras: 50. 1819. Blechnum raddianum Rosenst., Hedwigia 46: 91. 1906. Struthiopteris brasiliensis (Raddi) Maxon & C.V.Morton, Torrey Bot. Club 66: 43. 1939. Type: Brazil. Rio de Janeiro, Tijuca, without date, G. Raddi s.n. (Holotype: PI010197!; isotype: PI010198! (fertile frond)).

Blechnum itatiaiense Brade, Arq. Inst. Biol. Veg. 1(3): 225. 1935. Type: Brazil. Serra do Itatiaia, 21 June 1930, A. C. Brade 10115 (Lectotype [designated by Dittrich et al., 2018]: R000021796!; isolectotypes: BM000769805!, R000021796a!, RB00543238!, RB00561298!).

Plants terrestrial, rarely lithophytic; rhizomes erect or short-creeping, at the apex with narrow triangular scales, light to dark castaneous, abundant, 3.9-18.3 × 0.4-3.9 mm at the base, margin entire, denticulate or with elongated projections, the apex prolonged; fronds dimorphic, the sterile ones (16-102 cm long) shorter than the fertile (27-106 cm long); petiole stramineous to nigrescent near the base, stramineous to dark brown towards the apex, sterile fronds 6-60 cm long, 1-4 mm diam., scaly along the entire length or just near the base, the scales similar to those of rhizome, but smaller, lanceolate or triangular, fertile fronds 15-71 cm long.; sterile blades 10-48 × 6-21 cm, chartaceous to coriaceous, pinnate, ovate to oblong, terminal pinna conform; fertile blades 10-46 × 6-21 cm, ovate-lanceolate or oblong-lanceolate; rachises scaly or not, the scales light brown or castaneous, concolorous, 0.6-11.8 × 0.04-1.2 mm at the base, lanceolate to narrowly triangular, twisted, margins predominantly entire or rarely to regularly denticulate, sometimes with elongated projections; aerophores elongated, elliptical, discrete, present at the base of the petioles and/or at the base of the pinnae, sometimes absent; sterile pinnae 4-20 pairs, 4-15 × 1-1.7 cm, slightly to strongly ascending, lanceolate to falcate, petiolulate or sessile (the basal ones petiolulate, sessile towards the apex), the apical ones adnate on the basiscopic side, margins crispate to entire at the base, serrate only at the apex or throughout the whole margin, plane to slightly revolute, the apex of the pinnae prolonged, slightly to strongly acuminate or attenuate, with the presence of an hyaline margin surrounding the pinnae, on the abaxial costa with light brown scales, triangular to lanceolate, twisted, the apex prolonged or not, margin entire or denticulate, present mainly in the proximal portion of the pinnae, or absent; fertile pinnae 7-19 pairs, 4-15 × 0.3-0.4 cm, linear, without green tissue beyond the indusium; veins free, simple or once forked, with thickened tips at the margin; sori linear, continuous, parallel to the costae, scattered on the surface of the fertile pinnae, often leaving no naked green tissue; indusium linear, strongly and irregularly lacerate at the edges; spores monolete, equatorial diameter 39-61 µm, polar diameter 39-61 µm; perine with medium to large cristae (6-10 µm high), small to large areolae, and covered with filaments.

Notes. Parablechnum brasiliense can exhibit a pinnae apex that is slightly acuminate, similar to that of P. regnellianum, or a strongly acuminate or attenuate apex, like P. cordatum. When the pinnae apex is slightly acuminate, P. brasiliense can be distinguished from P. regnellianum by the margin of the apex, which is serrate, its teeth acroscopically oriented, and the tip often curved inwards, while in P. regnellianum it is dentate, with teeth oriented outwards from the margin. In addition, while P. regnellianum possesses only coriaceous pinnae, P. brasiliense may also possess chartaceous pinnae.

Parablechnum brasiliense and P. cordatum exhibit similar prolonged pinnae apices but can be distinguished by the sterile pinnae length in some cases. Generally, P. cordatum stands out as the larger of the two species, with sterile pinnae ranging from 10 to 29 cm, whereas P. brasiliense presents comparatively smaller sterile pinnae, ranging from 4 to 15 cm. However, occasional overlap in size occurs, and, in such instances, the spores can be used to distinguish them. The spores or cristae size do not differ significantly between them, but they do contrast in terms of filament numbers. In P. cordatum, the filaments are either absent or scarce, whereas P. brasiliense has abundant filaments covering its surface. As for P. regnellianum, the characteristics of spores may overlap with P. brasiliense, but they are easily distinguished by the aforementioned pinnae features.

Sehnem (1968) classified this species as B. regnellianum (= P. regnellianum) and noted that they are smaller than closely related species. Although P. brasiliense may have some large individuals, this species is smaller compared to P. cordatum and P. usterianum in most cases. Moreover, Sehnem (1968) cites the taxon B. euraddianum, which is a superfluous name assigned to the species Lomaria brasiliensis, which had already been transferred to Blechnum as B. raddianum.

A syntype of B. itatiaiense (A.C. Brade 10380) has not been located.

Distribution and habitat. There are records of the species in Brazil, Colombia, and Peru. In Brazil, it is distributed in the South (Rio Grande do Sul, Santa Catarina, and Paraná), Southeast (Rio de Janeiro, São Paulo, Espírito Santo, and Minas Gerais), and Midwest (Goiás) regions.

Parablechnum brasiliense grows in heterogeneous habitats, from sunny to shaded areas, closed forests, rocky environments, open fields, and even disturbed environments like roadsides. It is usually associated with moist environments near watercourses, such as rivers, streams, and waterfalls. Parablechnum brasiliense occurs between 220 and 1600 m a.s.l. in Brazil, but there are records of this species reaching 3500 m a.s.l. in Colombia (Beukema 161). It habits the Tropical Grasslands, Savannas, and Shrublands from the Midwest to the Southern regions of Brazil; the Tropical and Subtropical Moist Broadleaf Forests from Brazil, Peru, and Colombia; and Montane Grasslands and Shrublands in Colombia.

Specimens Examined. Brazil. s.d., Burchell 482 (K). ESPÍRITO SANTO: Castelo, Parque Estadual do Forno Grande, 20° 31’ 09” S, 41° 06’ 02” W, 11 July 2005, L. Kollmann 7971 (MBML); Iúna, Floresta do Senhor Aristides, 20° 21’ 43” S, 41° 28’ 14” W, 21 July 2015, J. P. F. Zorzanelli 1278 (VIES); Marechal Floriano, Sítio Bressan, 20° 24’ 46” S, 40° 40’ 59” W, 3 June 1994, G. M. F. Viégas 250 (VIES). GOIÁS: Chapada dos Veadeiros, Portal da Chapada, 14° 09’ 53” S, 47° 35’ 58” W, 24 November 2006, M. A. L. Rocha 98 (RB); idem, 1 km E of Alto Paraíso on road to Nova Roma, 14° 07’ 17” S, 47° 30’ 28” W, 05 March 1973, W. R. Anderson 6299 (K, UB); Catalão, Rodovia GO-330 (GO-053) Catalão-Ipameri, 18° 10’ 00” S, 47° 57’W, 23 January 1996, M. R. Pietrobom da Silva 2578 (SJRP); Cristalina, Cachoeira do Arrojado, 16° 47’ 35” S, 47° 31’ 27” W, 17 July 2007, R. F. Monteiro 83 (RB); Ipameri, Rodovia GO-213(GO-054) Ipameri-Caldas Novas, 17° 43’ 00” S, 48° 07’ 59” W, 23 January 1996, M. R. Pietrobom da Silva 2620 (SJRP). MINAS GERAIS: São Sebastião de Paraíso, 20° 54’ 38” S, 46° 59’ 10” W, 24 May 1945, A. C. Brade 17969 (RB); Serra do Espinhaço. Serra do Cipó, Minas Gerais, km 132, 19° 13’ 35” S, 43° 33’ 21” W, 17 February 1968, H. S. Irwin 20319 (UB); Barbacena, 21° 13’ 33” S, 43° 46’ 25” W, 20 June 1879, L. S. M. Netto s.n. (R); Carangola, Fazenda Neblina, 20° 42’ 59” S, 42° 28’ 59” W, May 1989, B. Cosenza 785 (RB); idem, 20° 42’ 59” S, 42° 28’ 59” W, 5 June 1988, L. S. Leoni 256 (RB); idem, 20° 42’ 59” S, 42° 28’ 59” W, June 1988, L. S. Leoni 694 (RB); Furnas, Região da Represa de Furnas, 20° 41’ 08” S, 46° 20’ 20” W, 28 September 2005, A. A. Arantes 1445 (HUFU); Juiz de Fora, 21° 44’ 03” S, 43° 22’ 40” W, 5 February 1948, P. Krieger 1162 (RB); Lima Duarte, Parque Estadual do Ibitipoca, 21° 42’ 59” S, 43° 52’ 59” W, 17 May 2006, R. C. Forzza 4191 (RB, NY); Ouro Preto, Distrito de Cachoeira do Campo, 20° 21’ 04” S, 43° 40’ 18” W, 8 June 2005, C. E. Jascone 360 (RB); idem, 20° 22’ 31” S, 43° 30’ 07” W, 01 February 1971, H. S. Irwin 29547 (UB); Poços de Caldas, Fonte dos Amores, 21° 49’ 11” S, 46° 41’ 05” W, 30 October 1997, A. M. Rosa 10 (SJRP); Rio Preto, 22° 05’ 21” S, 43° 49’ 39” W, 12 December 2019, F. Gonzatti 5454 (FURB); Santa Bárbara, Serra da Caraça, 19° 57’ 51” S, 43° 25’ 28” W, 06 December 1989, W. Oliveira 02 (SJRP); Serro, Estrada entre Milho Verde e São Gonçalo do Rio das Pedras, 18° 26’ 25” S, 43° 29’ 06” W, 10 April 2011, A. L. Gasper 2846 (FURB); Uberlândia, Fazenda Estiva, 19° 06’ 03” S, 48° 07’ 36” W, 23 December 2002,G. C. Oliveira 1837 (HUFU); Viçosa, Agricultural College land, 20° 44’ 59” S, 42° 52’ 57” W, 1 April 1930, Ynes Mexia 4546 (RB). PARANÁ: Adrianópolis, Boa Vista, 24° 39’ 26” S, 48° 59’ 28” W, 19 February 1981, G. Hatschbach 43618 (MBM); Cerro Azul, Rio do Turvo, 24° 49’ 25” S, 49° 15’ 40” W, 04 October 1973, G. Hatschbach 32651 (MBM); Curitiba, Centro Politécnico, 25° 29’ 41” S, 49° 25’ 48” W, 25 September 1987, Cervi 2476 (SJRP); Jaguariaíva, Vale do Codó, 24° 16’ 06” S, 49° 43’ 04” W, 13 July 2005, E. Barboza 1084 (MBM); idem, Parque Estadual do Cerrado, 24° 10’ 00” S, 49° 39’W, 28 August 1993,P. H. Labiak 51 (UPCB); Ponta Grossa, 25° 05’ 42” S, 50° 09’ 43” W, 29 December 1976, L. Krieger s.n. (VIES); Tibagi, Parque Estadual do Guartelá, 24° 30’ 34” S, 50° 24’ 49” W, 27 March 2010, C. Michelon 682 (MBM); idem, 24° 30’ 34” S, 50° 24’ 49” W, 29 October 2004, F. B. Matos 67 (MBM). RIO DE JANEIRO: s.d., Raddi, s.n. (PI?). Itatiaia, 22° 26’ 43” S, 44° 35’ 18” W, 22 Jun 1930, Brade 10115 (BM!, RB!). Miguel Pereira, Portão para Santana de Palmeira, 22° 33’ 48” S, 43° 26’ 37” W, 13 November 2001, L. S. Sylvestre 1528 (RB); Petrópolis, Gabinete de Botanica da Escola Politecnica 5305, 22° 28’ 47” S, 43° 12’ 23” W, 1879, F. R. Galvão s.n. (R); Rio de Janeiro, Pedra da Gávea, 22° 59’ 56” S, 43° 16’ 59” W, 7 November 1971,D. Sucre 7419 (RB); idem, 22° 59’ 56” S, 43° 16’ 59” W, 8 February 2007, R. C. Forzza 4474 (RB); Teresópolis, 22° 10’ 43” S, 42° 53’ 02” W, January 1943, Fritz de Lauro,s.n. (RB); idem, Parque Nacional da Serra dos Órgãos, 22° 24’ 44” S, 42° 58’ 36” W, 13 September 2007, L. S. Sylvestre 2118 (RB); idem, Parque Nacional da Serra dos Órgãos, 22° 12’ 17” S, 42° 53’ 51” W, 24 February 2005, R. A. Engelmann 243 (RB); idem, 22° 12’ 18” S, 42° 53’ 46” W, 9 November 2004, R. A. Engelmann 61 (RB). Tijuca, without date, G. Raddi s.n. (PI!). RIO GRANDE DO SUL: São José dos Ausentes, Distrito Silveiras, Pico Monte Negro, 28° 44’ 55” S, 50° 03’ 56” W, 27 April 1997, P. G. Windisch 8743 (SJRP). SANTA CATARINA: Angelina, Linha do Chaves, 27° 32’ 24” S, 48° 57’ 36” W, 6 April 2010, A. Stival-Santos 2383 (FURB); Anitápolis, Rio das Pedras, 27° 54’S, 49° 08’ 24” W, 14 July 2011, A. Korte7066 (FURB); idem, Rio do Meio, 27° 54’ 07” S, 49° 07’ 43” W, 30 July 2017, F. Gonzatti 3764 (UPCB); Bom Jardim da Serra, Morro da Igreja, 28° 07’ 24” S, 49° 28’ 48” W, 8 April 2010, A. Salino 14750 (FURB); Orleans, Trilha Pedra Furada, 28° 08’ 02” S, 49° 28’ 45” W, 11 March 2018, A. Kassner-Filho 2599 (FURB); Palhoça, Maciambú, 27° 48’ 36” S, 48° 41’ 24” W, 19 June 2010, A. Stival-Santos 3035 (FURB); São Bento do Sul, CEPA, 26° 19’ 25” S, 49° 18’ 26” W, 30 March 2007, A. L. Gasper 94 (FURB); idem, Sertãozinho, 26° 19’ 02” S, 49° 24’ 22” W, 23 October 2016, P. Schwirkowski 1990 (FURB); Urubici, Corvo Branco, 28° 03’ 16” S, 49° 22’ 07” W, 10 September 2019, A. L. Gasper 540 (FURB); idem, Parque Nacional de São Joaquim, 28° 08’ 38” S, 49° 37’ 45” W, 24 January 2020, L. A. Funez 9556 (FURB); SÃO PAULO: Analândia, Serra do Cuscuzeiro, 22° 07’ 34” S, 47° 39’ 54” W, 02 July 1988, A. Salino 482 (SJRP); idem, 22° 07’ 34” S, 47° 39’ 54” W, 13 November 1994, R. A. Santana 19 (SJRP); Batatais, 20° 53’ 59” S, 47° 36’ 08” W, 09 December 1990, P. Sandrin 11 (SJRP); Cachoeira Paulista, 22° 40’ 25” S, 44° 59’ 50” W, 09 December 2019, F. Gonzatti 5319 (FURB); Campos do Jordão, Horto Florestal, 22° 43’ 58” S, 45° 35’ 24” W, 1 June 1984, A. Santos 234 (RB); Cruzeiro, 22° 34’ 35” S, 44° 57’ 48” W, 10 December 2019, F. Gonzatti 5338 (FURB); Cunha, Reserva (Núcleo) de Cunha, 23° 04’ 23” S, 44° 57’ 58” W, 15 May 1992, M. R. Pietrobom da Silva 457 (SJRP); Iporanga, Parque Estadual Turístico do Alto Ribeira, 24° 32’ 22” S, 48° 41’ 36” W, 21 September 2011, F. F. F. Mazziero 692 (UNIP); José Bonifácio, Fazenda Santa Clara, 21° 03’S, 49° 42’W, 06 May 1997, F. R. Nonato 318 (SJRP); Pirangi, 21° 05’ 23” S, 48° 40’ 10” W, 12 November 1995, C. Zanetoni 03 (SJRP); Santa Rosa de Viterbo, Fazenda Cascata, 21° 28’ 12” S, 47° 21’ 36” W, 15 October 1985, F. F. Zanoelo 08 (SJRP); Ubatuba, Rodovia Rio-Santos (SP 055), km 13, 23° 01’ 59” S, 45° 04’ 00” W, 01 January 2003, F. P. F. Athayde 1145 (SJRP). Colombia. 6° 18’N, 75° 28’ 59” W, 30 April 1996, J. A. Posada 53 (MBM); PUTUMAYO: Páramo de San Antonio, road from Pasto to Sibundoy, 0° 30’ 37”N, 75° 52’ 58” W, 13 March 1953, R. E. Schultes s.n. (L); RISARALDA: PNN Los Nevados, 4° 47’ 30”N, 75° 19’ 59” W, 01 January 1991, H. Beukema 161 (L); Peru. AMAZONAS: East of Balsas, 4° 54’ 40” S, 77° 59’ 03” W, 22 May 912, W. H. Osgood 72 (F).

Parablechnum cordatum (Desv.) Gasper & Salino, Phytotaxa 275:216. 2016. Lomaria cordata Desv., Mag. Neuesten Entdeck. 5: 330. 1811. Lectotype (here designated): Peru. Concepción, without date, Dombey s.n. (P00307042!). Blechnum cordatum (Desv.) Hieron., Hedwigia 47: 239. 1908.

Blechnum macahense Brade, Anais Reunião Sul-Amer. Bot. 2: 6. 1940. Lectotype (here designated): Brazil. Rio de Janeiro, Macaé, Frade Macaé, 19 June 1937, A.C. Brade 15801 & Santos Lima (HB38760!).

Plants terrestrial, rarely lithophytic; rhizomes erect or short-creeping, at the apex with abundant narrowly triangular light-castaneous scales, 7.4-18.5 × 0.8-2.8 mm at the base, margin entire or denticulate, with prolonged apex; fronds dimorphic, the sterile ones (60-198 cm long) shorter than the fertile (80-204 cm long); petiole stramineous to dark-castaneous on most of the length, stramineous to nigrescent near the base, sterile fronds 35-114 cm long, 2-6 mm diam., scaly only near the base or mid-portion, the scales similar to those of rhizome but smaller; of fertile fronds 55-137 cm long; sterile blades 33-84 × 19-34 cm, coriaceous to chartaceous, pinnate, ovate to oblong, terminal pinna conform; fertile blades 30-67× 8-24 cm, ovate-lanceolate or oblong-lanceolate; rachises scaly, the scales light-brown, concolorous 1.3-9.2 × 0.1-0.8 mm at the base, lanceolate to narrowly triangular, twisted, with prolonged apex, margins predominantly entire or rarely to regularly denticulate; aerophores elongated, elliptical, discrete, present at the base of the petioles and/or at the base of the pinnae, sometimes absent; sterile pinnae 9-24 pairs, 10-29 × 1.2-4.3 cm, slightly to strongly ascending, lanceolate to slightly falcate, petiolulate or sessile (the basal ones petiolulate, sessile towards the apex), the apical ones adnate on the basiscopic side, margins crispate to entire at the base, serrate towards the apex, plane to slightly revolute, the apex of the pinnae prolonged, strongly acuminate to attenuate, with a hyaline margin surrounding the pinnae, on the abaxial costa with scales similar to those of the rachis mainly in the proximal portion of the pinnae; fertile pinnae 9-23 pairs, 8-22 × 0.3-0.5 cm, linear, not contracted to slightly contracted, without green tissue beyond the indusium; veins free, simple or once forked, with thickened tips at the margin; indusium linear, strongly and irregularly lacerate at the edges; spores monolete, equatorial diameter 42-65 µm, polar diameter 42-63 µm; perine with large cristae (7-13 µm high) and areolae (at least 30 µm long), with rare or absent filaments.

Notes. Parablechnum cordatum stands out among the other analyzed species due to its larger size. Its pinnae can reach up to 29 cm in length, whereas the second largest pinnae in the complex belongs to P. brasiliense, reaching a maximum length of 15 cm. The blades of P. cordatum are also larger, sometimes reaching twice the size of those in the other species. In instances where smaller specimens of P. cordatum overlap in size with P. brasiliense, distinguishing them becomes challenging due to morphological similarities. Usually, P. cordatum exhibits a notably elongated apex, where in P. brasiliense, the apex is shorter. Apart from this distinction, their other characteristics closely resemble each other, and morphology alone may not be enough to differentiate them. In these cases, the distinction can be made by examining both species under SEM: Parablechnum cordatum spores possess few or no filaments, whereas P. brasiliense spores display abundant filaments covering their surface.

Parablechnum cordatum can be distinguished from P. usterianum primarily by its pinnae apex. In the case of the latter, the apex is cuneate, a pronounced contrast when compared to the attenuated apex and elongated extensions observed in P. cordatum. As for P. regnellianum, distinctions lie in various factors, including the pinnae apex, pinnae length and its margins, and spore features (Tab. 2, Figs. 1, 2). Differently from P. cordatum, in P. regnellianum, the pinnae apex is acute, with no elongated extensions, the pinnae are smaller, and the pinnae margins are dentate. The spores differ greatly, with small cristae and areolae, and numerous filaments in P. regnellianum.

The specimen designated as the holotype of P. cordatum has been historically cited without a formal publication of it. The original publication by Desvaux (1811) does not make any reference to a holotype, a locality, or even a collector number. In this context, we have officially assigned a lectotype for P. cordatum, selecting the individual traditionally acknowledged as its holotype (Dombey s.n., P). Due to the absence of a collector number in the individual, we were unable to confirm the existence of duplicates, and specimens typically considered isotypes cannot be classified as isolectotypes.

Furthermore, the originally designated holotype of B. macahense (A.C. Brade & Santos Lima 15801, RB) remains lost. Despite our request for the R herbarium to locate the specimen, it has not been found, and there are no available online images for reference. Hence, we have assigned a lectotype from an isotype to replace the missing holotype.

Distribution and habitat. We analyzed specimens from Bolivia, Brazil, Colombia, Ecuador, and Peru. It is implied that the species may extend beyond these regions, assuming that its distribution remains unknown. In Brazil, it can be found in the South (Rio Grande do Sul, Santa Catarina, and Paraná), Southeast (Rio de Janeiro, São Paulo, Espírito Santo, and Minas Gerais), and Midwest (Mato Grosso) regions. It grows in forests or open fields (like hillsides), roadsides, and trails, and it is usually found in humid habitats associated with bodies of water and moist soils. The species is rarely lithophytic and can also occur as an accidental epiphyte. Parablechnum cordatum can be found between 50 and 2450 m a.s.l. and has the most extensive distribution in the complex. It habits mostly of the Tropical and Subtropical Moist Broadleaf Forests in Brazil, Bolivia, Colombia, Ecuador, and Peru, but also the Tropical and Subtropical Grasslands, Savannas, and Shrublands in Brazil, the Tropical and Subtropical Dry Broadleaf Forests in Colombia, and the Mangroves in Brazil.

Specimens Examined. Bolivia. COCHABAMBA: 16° 27’ 16” S, 65° 28’ 51” W, 23 February 1929, s.c.,s.n. (F); idem, 16° 30’ 22” S, 65° 29’ 47” W, 23 February 1929, s.c., s.n. (F). La Paz: La Paz, 15° 30’S, 68°W, 27 January 1989, R. Seidel 1442 (F); idem, 16° 12’ 02” S, 67° 43’ 04” W, 11 March 1979, S. G. Beck 511 (F); Larecaja, Tipuani, 15° 29’ 54” S, 68° 19’ 56” W, 01 February 1920, O. Buchtien5131 (F); Sud Yungas, La Paz-Chulumani Road, 16° 15’S, 67° 30’W, 03 August 1989, A. Fay 2571 (SJRP). Brazil. ESPÍRITO SANTO: Alto Limoeiro, 19° 52’ 08” S, 40° 52’ 35” W, 14 May 1946, A. C. Brade 18208 (RB); Castelo, Trilha para o Forninho, 20° 30’ 58” S, 41° 05’ 01” W, 17 July 2008, P. H. Labiak 4805 (RB); Iúna, Floresta do Senhor Aristides, 20° 21’ 46” S, 41° 28’ 15” W, 14 August 2015, J.P.F. Zorzanelli 1306 (VIES); Santa Teresa, Estação Biológica de Santa Lúcia, 19° 58’ 17” S, 40° 31’ 49” W, 26 September 1993, G. M. F. V. Aquije 162 (MBML); idem, Estação Biológica de Santa Lúcia, 19° 58’ 17” S, 40° 31’ 49” W, 20 August 1985, H. Q. Boudet Fernandes 1433 (MBML); idem, Nova Lombardia, 19° 54’ 11” S, 40° 34’ 07” W, 15 May 1985, H. Q. Boudet Fernandes 1139 (MBML); idem, Penha, Propriedade do Dr. Tabajára, 19° 57’ 06” S, 40° 33’ 45” W, 30 January 1986, H. Q. Boudet Fernandes 1813 (MBML); idem, Estação Biológica Caixa D’Água, 23° 13’ 00” S, 46° 57’W, 11 April 1985, J. Prado 2051 (UEC); idem, Reserva Biológica Augusto Ruschi - Nova Lombardia, 19° 54’ 27” S, 40° 33’ 11” W, 15 July 2003, J. Rossini 388 (MBML); idem, Estação Biológica de Santa Lúcia, 19° 58’ 17” S, 40° 31’ 49” W, 11 July 2007, P. H. Labiak4012 (MBML); idem, Reserva Biológica Augusto Ruschi, 19° 54’ 27” S, 40° 33’ 11” W, 08 January 2003, R. A. Krause 29 (MBML); idem, Reserva Biológica Augusto Ruschi, 19° 54’ 27” S, 40° 33’ 11” W, 08 January 2003, R. A. Krause 31 (MBML); idem, Reserva Biológica Augusto Ruschi, 19° 54’ 27” S, 40° 33’ 11” W, 25 September 2002, R. R. Vervloet 1078 (MBML); idem, Penha, 19° 57’ 12” S, 40° 33’ 10” W, 10 April 1984, W. A. Hoffmann 25 (MBML); idem, Estação Biológica Caixa D’Água, 19° 55’ 53” S, 40° 36’ 27” W, 11 April 1985, W. Boone 350 (MBML). MATO GROSSO: Itiquira, Rodovia MT 299, entroncamento com a BR 364 a Itiquira, 17° 12’S, 54° 07’ 00” W, 22 February 1994, C. E. Rodrigues Jr. 703 (SJRP). MINAS GERAIS: Ibitipoca, 21° 50’ 18” S, 43° 47’ 28” W, 10 July 1896, Schwacke 12322 (RB); Bocaina de Minas, Parque Nacional do Itatiaia, 22° 17’ 08” S, 44° 36’ 48” W, 30 October 2004, J. P. Condack301 (NY); idem, Parque Nacional do Itatiaia, Alto dos Brejos, 22° 17’ 08” S, 44° 36’ 48” W, 16 September 2004, J. P. S. Condack 266 (RB); Caparaó, Parque Nacional do Caparaó, 20° 31’ 23” S, 41° 54’ 16” W, 29 April 1989, A. Salino 25784 (UEC); Carangola, Fazenda São Sebastião, 20° 43’ 59” S, 42°W, 24 March 1988, L. S. Leoni 66 (RB); Juiz de Fora, Parque da Lajinha, 21° 46’ 59” S, 43° 21’ 59” W, 21 November 2013, L. V. Lima 21 (HSTM); Lima Duarte, Parque Estadual do Ibitipoca, 21° 42’ 09” S, 43° 52’ 18” W, 9 August 2005, C. Mynssen 797 (RB); Monte Belo, Fazenda Queimada Grande, 21° 24’S, 46° 16’ 59” W, 07 September 1987, A. H. Gentry 59148 (UEC); Ouro Preto, Parque Estadual do Itacolomi, 20° 23’ 00” S, 43° 30’ 12” W, 9 June 2005, C. E. Jascone 393 (RB); idem, Parque Estadual do Itacolomi, 20° 24’ 35” S, 43° 24’ 59” W, 24 March 2004, C. Mynssen 581 (RB); Santana de Pirapama, Serra do Cipó, 19° 53’ 25” S, 44° 58’ 45” W, 24 November 2009, D. C. Zappi 2509 (RB). PARANÁ: Antonina, Usina Hidrelétrica Parigot de Souza, 25° 25’ 43” S, 48° 42’ 43” W, 05 October 2006, J. M. Silva 5008 (MBM); Balsa Nova, Serra São Luís, 25° 35’ 02” S, 49° 38’ 08” W, 17 July 1970, G. Hatschbach24469 (MBM); Guaratuba, Pico Pedra Branca de Araraquara, 25° 55’ 36” S, 48° 53’ 41” W, 12 August 2014, J. Cordeiro 5202 (FLOR, MBM); Lapa, Gruta do Monge, 25° 46’ 11” S, 49° 42’ 57” W, 10 June 2008, J. Cordeiro 2933 (MBM); Morretes, Rod. BR277, 25° 28’ 23” S, 48° 49’ 44” W, 17 January 1969, G. Hatschbach 20824 (RB); idem, BR277, estrada do Arraial, 25° 28’ 37” S, 48° 50’ 04” W, 17 January 1969, G. Hatschbach 390 (MBM); Paranaguá, Picadão Cambará, 25° 31’ 12” S, 48° 30’ 33” W, 14 February 1968, G. Hatschbach 18691 (MBM); Ponta Grossa, Parque Estadual de Vila Velha, 25° 13’ 59” S, 50°W, 14 December 2004, P. B. Schwartsburd431 (NY); Quatro Barras, Parque Estadual Serra da Baitaca, 25° 21’ 56” S, 49° 04’ 37” W, 24 July 2016, B. K. Canestraro 964 (MBM); Tibagi, Fazenda Monte Alegre, Rio Laranjeira, 24° 30’ 34” S, 50° 24’ 49” W, 29 March 1953, G. Hatschbach 3059 (MBM); Tijucas do Sul, Tabatinga, 25° 55’ 41” S, 49° 11’ 56” W, 11 January 1983, Y. S. Kuniyoshi 4594 (MBM). RIO DE JANEIRO: Guapimirim, Trilha do São Pedro, 22° 27’ 40” S, 43° 01’ 31” W, 13 July 2010, R. A. Engelmann 769 (RB); Itatiaia, Macieiras, 22° 29’ 45” S, 44° 33’ 37” W, 26 March 1943, E. C. Pereira 350 (IAN); 1837, Gardner 143 (K); idem, 22° 29’ 29” S, 44° 33’ 37” W, August 1933, A. C. Brade 12621 (RB); idem, Trilha Rui Braga, próximo ao Abrigo Macieiras, 22° 25’ 02” S, 44° 38’ 07” W, 24 November 2009, E. R. Damasceno 358 (RB); idem, Parque Nacional do Itatiaia, Planalto, 22° 15’S, 44° 33’ 59” W, 8 September 2004, J. P. S. Condack 235 (RB); idem, Parque Nacional do Itatiaia, Estr. para o Planalto, 22° 17’ 08” S, 44° 36’ 48” W, 22 August 2005, J. P. S. Condack 439 (RB); idem, 28 August 1989, L. S. Sylvestre 277 (RB); idem, PARNA Itatiaia, 22° 29’ 29” S, 44° 35’ 23” W, 11 February 1990, M. F. Morel 121 (SJRP); idem, Parque Nacional de Itatiaia, Maromba, 22° 29’ 29” S, 44° 33’ 37” W, 5 February 1942, W. D. Barros 588 (RB); Macaé, Estrada do Rio Frade de Macaé, 19 Feb 1937, Brade 15801 (HB!). Magé, Santo Aleixo, 22° 30’ 36” S, 43° 01’ 56” W, 3 May 2011, R. A. Engelmann 1792 (RB); Miguel Pereira, Reserva Biológica do Tinguá, 22° 27’ 04” S, 43° 28’ 02” W, 13 July 2007, L. S. Sylvestre 2103 (NY, RB); Petrópolis, 22° 29’ 24” S, 43° 07’ 31” W, 1872, T. A. Preston s.n. (K); Rio de Janeiro, Sumaré, 22° 56’ 28” S, 43° 13’ 30” W, 16 March 1962, A. P. Duarte 6285 (K); idem, Sumaré, 22° 57’ 09” S, 43° 14’ 05” W, 19 September 2012, C. Mynssen 1363 (RB); Idem, Sumaré, 22° 57’ 09” S, 43° 14’ 05” W, 19 September 2012, C. Mynssen 1354 (RB); São Fidélis, Serra do Itacolomi, Subida para a Pedra do Macaco, 21° 51’ 02” S, 41° 52’ 30” W, 31 August 2016, C. Baez 1038 (RB); Teresópolis, Parque Nacional da Serra dos Órgãos, 24 February 2005, R. A. Engelmann 244 (RB). RIO GRANDE DO SUL: São Francisco de Paula, Aratinga, 29° 21’ 16” S, 50° 10’ 39” W, 01 September 2015, F. Gonzatti 2078 (FURB, MBM). SANTA CATARINA: Águas Mornas, Rio Miguel, 27° 43’ 13” S, 48° 57’ 39” W, 13 October 2010, A. Korte 4596 (FURB); idem, Canto do Schutch, 27° 37’ 48” S, 48° 52’ 12” W, 20 February 2010, A. Stival-Santos 1770 (FURB); Alfredo Wagner, Soldadinho, 27° 37’ 45” S, 49° 24’ 39” W, 28 November 2009, A. Korte 1097 (FURB); Angelina, Rio Fortuna, 27° 27’ 02” S, 49° 03’W, 8 April 2010, A. Stival-Santos 2633 (FURB); Antônio Carlos, Santa Maria, 27° 32’ 22” S, 48° 52’ 13” W, 5 February 2010, A. Stival-Santos 1696 (FURB); Apiúna, Faxinalzinho, 27° 10’ 49” S, 49° 23’ 37” W, 17 March 2010, A. Korte 2160 (FURB, MBM); idem, 27° 02’ 08” S, 49° 23’ 23” W, 16 October 2006, N. L. de Souza s.n. (FURB); Biguaçu, Sorocaba do Sul, 27° 21’ 36” S, 48° 46’ 48” W, 6 July 2010, A. Stival-Santos 3211 (FURB); Blumenau, Bairro Garcia, 26° 55’ 10” S, 49° 03’ 58” W, 24 October 2004, A. L. Gasper 153 (FURB); idem, Parque Nacional da Serra do Itajaí, 27° 03’ 24” S, 49° 05’ 16” W, 17 August 2007, A. L. Gasper 572 (FURB); idem, Parque Nacional da Serra do Itajaí, 27° 03’ 24” S, 49° 05’ 16” W, 22 March 2007, A. L. Gasper 664 (FURB); idem, Parque Nacional da Serra do Itajaí, Trilha da Chuva, 27° 03’ 14” S, 49° 05’ 05” W, 20 September 2014, F. Bittencourt 202 (FURB); idem, Spitzkopf, 27° 01’ 35” S, 49° 07’ 28” W, 09 October 2012, L. A. Funez 1067 (FURB); idem, Spitzkopf, 27° 00’ 44” S, 49° 06’ 41” W, 09 October 2012, L. A. Funez 1098 (FURB); idem, Spitzkopf, 27° 01’ 23” S, 49° 07’ 07” W, 26 August 1998, L. Sevegnani s.n. (FURB); Botuverá, Reserva Biológica Canela Preta, 27° 16’ 12” S, 49° 08’ 24” W, 30 March 2010, A. Stival-Santos 2279 (FURB); Doutor Pedrinho, Ribeirão Rigo, 26° 43’ 48” S, 49° 29’ 58” W, 4 May 2010, S. Dreveck 2185 (FURB); Grão Pará, PAESF, 28° 11’ 21” S, 49° 23’ 24” W, 10 September 2017, R. Colares s.n. (CRI); idem, 28° 11’ 12” S, 49° 12’ 46” W, 25 July 2011, S. Z. Custódio s.n. (CRI); Imaruí, Parque Estadual da Serra do Tabuleiro, 28° 10’ 10” S, 48° 52’ 13” W, 17 March 2010, M. Verdi 4047 (FURB, MBM); Indaial, Parque Nacional da Serra do Itajaí, 27° 05’ 24” S, 49° 13’ 51” W, 21 May 2010, A. Korte 3392 (FURB); Jaraguá do Sul, Estrada para as Minas de Caulin, 26° 16’ 56” S, 49° 13’ 18” W, 11 December 2012, A. L. Gasper 3051 (FURB); Joinville, Serra Dona Francisca, 26° 13’ 15” S, 49° 03’ 13” W, 01 January 2016, P. Schwirkowski 1424 (FURB); Leoberto Leal, Rio Feijão, 27° 27’ 01” S, 49° 13’ 50” W, 5 November 2009, A. Korte 752 (FURB); Major Gercino, 27° 26’ 58” W, 49° 08’ 24” S, 20 April 2010, A. Stival-Santos 2516 (FURB); Massaranduba, Serra do Jacu, 26° 33’ 01” S, 49° 03’ 02” W, 4 February 2011, A. Korte 5908 (FURB); Morro Grande, Três Barras, 28° 42’ 36” S, 49° 46’ 12” W, 11 December 2009, J. L. Schmitt 952 (FURB); Nova Trento, Rio Veado, 27° 21’ 38” S, 49° 08’ 13” W, 29 September 2010, A. Korte 4532 (FURB); Orleans, Rio Minador, 28° 10’ 12” S, 49° 24’ 36” W, 9 December 2009, J. L. Schmitt 828 (FURB); Palhoça, Morro do Cambirela, 27° 38’ 43” S, 48° 40’ 04” W, 15 December 1971, A. Bresolin 437 (MBM); Paulo Lopes, Sertão do Campo, 27° 52’ 44” S, 48° 45’ 43” W, 01 February 2010, J. L. Schmitt 1243 (FURB); idem, Sertão do Campo, 27° 52’ 44” S, 48° 45’ 43” W, 5 June 2010, J. L. Schmitt 2668 (FURB); idem, Espraiado/Parque Estadual da Serra do Tabuleiro, 27° 59’ 24” S, 48° 46’ 48” W, 8 June 2010, M. Verdi 4909 (RB); idem, Espraiado/Parque Estadual da Serra do Tabuleiro, 27° 59’ 24” S, 48° 46’ 48” W, 8 June 2010, M. Verdi 4909 (FURB, RB); idem, Sertão do Campo/Parque Estadual da Serra do Tabuleiro, 27° 53’ 36” S, 48° 45’ 21” W, 10 June 2010, M. Verdi 4938 (FURB); Ponte Alta, Morro do Funil, 27° 16’ 30” S, 50° 07’ 57” W, 25 March 2008, A. L. Gasper 1668 (FURB); Rancho Queimado, Mato Francês, 27° 37’ 47” S, 49° 08’ 39” W, 27 April 2009, S. Dreveck 858 (FURB); Rio do Campo, Anta Branca (Antigo Alto Rio do Oeste), 26° 54’ 36” S, 50° 13’ 13” W, 22 February 2010, A. Korte 1921 (FURB); Rodeio, São Pedro, 26° 54’ 37” S, 49° 24’ 41” W, 30 March 2010, A. Korte 2335 (FURB); São Bento do Sul, CEPA Rugendas UNIVILLE, APA Municipal do Rio Vermelho, 26° 19’ 21” S, 49° 18’ 33” W, 13 April 2014, F. Bittencourt 54 (FURB); idem, Minas de caulim, 26° 17’ 34” S, 49° 12’ 59” W, 07 March 2015, P. Schwirkowski 1082 (FURB); idem, Rio Natal, 26° 20’ 28” S, 49° 18’ 41” W, 04 June 2015, P. Schwirkowski 1152 (FURB); idem, Rio Vermelho, 26° 18’ 30” S, 49° 18’ 44” W, 28 September 2019, P. Schwirkowski 3489 (FURB); idem, APA Rio Vermelho, 26° 19’ 52” S, 49° 18’ 50” W, 10 October 2010, S. Dreveck 2549 (FURB); Siderópolis, Serrinha, 28° 37’ 12” S, 49° 35’ 24” W, 17 May 2010, J. L. Schmitt 2423 (FURB); idem, Reserva Biológica Estadual do Aguaí, 28° 32’ 58” S, 49° 36’ 14” W, 15 June 2009, M. Verdi 2346 (FURB); Taió, Gramado, 27° 00’ 01” S, 50° 13’ 14” W, 15 September 2010, A. Korte 4315 (FURB); Vidal Ramos, Mulungu, 27° 27’S, 49° 19’ 12” W, 14 September 2009, A. Korte 139 (FURB); Vitor Meireles, Jacú-Paca, 26° 49’ 18” S, 49° 46’ 12” W, 24 June 2010, A. Korte 3881 (FURB). SÃO PAULO: Between Santos and São Paulo, May 1942, C. Sandeman s.n. (K); Serra da Bocaina, 22° 40’ 29” S, 44° 36’ 28” W, 28 April 1951, A. C. Brade 20770 (RB); Cassia dos Coqueiros, Margens do rio Boiadeiro, 21° 19’ 59” S, 47° 07’ 59” W, 21 January 1997, F. R. Nonato 307 (SJRP); Iguape, Reserva Ecológica de Juréia, 24° 41’ 52” S, 47° 33’ 27” W, 16 August 1990, J. Prado 361 (RB); Mirassol, Instituto Penal Agrícola, 20° 48’ 36” S, 49° 31’ 12” W, 30 September 1992, C. E. Rodrigues Jr. 258 (SJRP); idem, Instituto Penal Agrícola, 20° 48’ 36” S, 49° 31’ 12” W, 10 March 1995, M. R. Pietrobom da Silva 2216 (SJRP); Ubatuba, Parque Estadual da Serra do Mar, 23° 25’ 48” S, 45° 04’ 12” W, 19 June 2008, M. L. B. Paciência 2967 (UEC). Colombia. 6° 18’E, 75° 28’ 59”N, 23 April 1996, J. A. Posada 218 (MBM); ANTIOQUIA: Frontino, Parque Nacional Natural Las Orquídeas, 6° 38’ 21”N, 76° 12’ 30” W, 11 September 2012, M. A. Sundue3352 (NY). HUILA: Cordillera Oriental, vertiente occidental, 2° 29’ 55”N, 75° 30’ 51” W, 20 March 1940, J. Cuatrecasas8369 (US). Valle del Cauca: 3° 45’N, 76° 30’W, 1958, s.c. 2696 (F); 3° 27’ 01”N, 76° 32’ 11” W, 26 October 1944, J. Cuatrecasas18289 (F); 3° 45’N, 76° 30’W, 20 October 1946, J. Cuatrecasas22380 (F). Ecuador. 1° 27’ 46” S, 78° 11’ 13” W, 19 January 1933, E. Heinrichs 250 (F); cerca el camino en el bosque primero Pastaza, 1° 26’ 41” S, 78° 06’ 58” W, 16 March 1985, N. Trushell 1104 (NY); 1° 27’ 46” S, 78° 11’ 13” W, 31 January 1934, H. Schimpff 673 (F). Peru. AMAZONAS: between Bagua and Imacita, 5° 16’ 57” S, 78° 23’ 10” W, 7 March 1998, H. H. van der Werff 14467 (NY). CHANCHAMAYO: Junín, 11° 01’ 00” S, 75° 06’ 03” W, 01 February 1939, s.c.,s.n. (F). CONCEPCIÓN: J. Dombey,s.n. (BM!, P!). CUZCO: 12° 30’S, 72° 30’W, 7 June 1977, J. C. Solomon 3169 (F). HUÁNUCO: 9° 29’ 00” S, 75° 50’ 25” W, 12 December 1953, P. Coronado 59 (US). JUNÍN: Concepción, 11° 55’ 00” S, 75° 16’ 59” W, 16 April 1923, G. S. Bryan 386 (F). PASCO: Oxapampa, 10° 34’ 59” S, 75° 31’ 59” W, 26 January 1984, D. N. Smith 5883 (F); idem, 10° 34’ 00” S, 72° 22’ 00” W, 6 July 1984, D. N. Smith 7647 (F); idem, 10° 30’S, 72° 03’W, 9 July 2003, H. van der Werff18175 (F).

Parablechnum regnellianum (Kunze) G.M.O.Machado & Gasper comb. nov. (Fig. 2). Lomaria regnelliana Kunze, Linnaea 22(5): 576. 1849. Blechnum regnellianum (Kunze) C.Chr., Index Filicum, Supplementum: 17. 1913. Type: Brazil. Minas Gerais, Caldas, 10 February 1846, A. F. Regnell #I. 490 (lectotype [designated by Ramos Giacosa, 2016]: B, 20 0033168!; isolectotypes: BM000769810!, S12-25786!, S05-9988!, S05-9986!, US00067439!, US01100895!).

Blechnum simileSehnem, Fl. Il. Catarin. 1 (fasc. BLEC): 56. 1968. Type: Brazil. Rio Grande do Sul, Aparados da Serra, Passo da Guarda, 16 January 1952, A. Sehnem 5861 (holotype: PACA069078!).

Plants terrestrial, rarely lithophytic; rhizomes short-creeping, elongated or not, sometimes forming a stolon, rarely erect, at the apex with abundant narrowly triangular light-castaneous scales, 3.4-12 × 0.3-2.8 mm at the base, margin entire or denticulate, with prolonged apex; fronds dimorphic, the sterile ones 10-73 (115) cm long, shorter than the fertile ones, 20-71 (150) cm long; petiole stramineous to dark-castaneous on most of the length, dark brown to nigrescent near the base, sterile fronds 2.5-43 (67) cm long, 1-3 mm diam., scaly along the entire length or just near the base, the scales similar to those of rhizome but smaller, with a lanceolate or triangular form, fertile fronds 10-41 (107) cm long.; sterile blades 6-30 (48) × 3-20 cm, coriaceous, pinnate, narrowly ovate, terminal pinna conform; fertile blades 7-31 (46) × 2-10 cm, ovate-lanceolate or oblong-lanceolate; rachises scaly or not, the scales light-brown or castaneous, concolorous, 3-9.8 × 0.1-1.1 mm at the base, lanceolate to linear, twisted, margins predominantly entire, rarely denticulate; aerophores elongated, discrete, present at the base of the petioles or/and at the base of the pinnae, or absent; sterile pinnae 3-15 pairs, 3-12 × 0.7-1.8 cm, slightly to strongly ascending, lanceolate, petiolulate or sessile (the basal ones petiolulate, sessile towards the apex), the apical ones adnate on the basiscopic side, margins crispate to entire at the base, dentate towards the apex, plane to slightly revolute, the apex acute to slightly acuminate, with a hyaline margin surrounding the pinnae, on the abaxial costa with light brown to whitish scales, linear to lanceolate, twisted, margin entire, present mainly in the proximal portion of the pinnae, or absent; fertile pinnae 4-17 pairs, 3-11 × 0.2-0.4 cm, linear, without green tissue beyond the indusium; veins free, simple or once forked, with thickened tips at the margin; indusium linear, strongly and irregularly lacerate at the edges; spores monolete, equatorial diameter 38-50 µm, polar diameter 39-61 µm; perine with small cristae (2-5.5 µm high) and areolae (5-15 µm long), and covered with filaments.

Notes. Parablechnum regnellianum may possess an elongated rhizome that can form a stolon (Fig. 2 C ), but this is not always present in every herbarium individual, since there are many incomplete samples. In cases where the rhizome is absent, it closely resembles P. cordatum and P. usterianum. A key distinguishing feature is the pinnae apex, which is round, acute, or slightly acuminate in P. regnellianum. In contrast, the other two species exhibit a pinnae apex with an elongated projection, whilst in P. regnellianum this projection is absent, or it may appear very tiny. If P. regnellianum does present this slightly acuminate apex, it can resemble P. brasiliense. The two species can be distinguished by the margin of the pinnae apex, which is dentate, with teeth that extend outwards from the margin in P. regnellianum, while P. brasiliense is serrate, with teeth acroscopically oriented and with the tip often curved inwards. Regarding the differentiation between P. brasiliense and P. cordatum, several factors set them apart, including the pinnae apex, pinnae length and its margins, and spore features (Tab. 2, Figs. 1, 2). In P. cordatum, the pinnae apex is attenuated, with elongated extensions, which are absent or may appear very small in P. regnellianum. Additionally, P. cordatum pinnae are bigger, with the apex with serrate margins.

Parablechnum regnellianum is primarily characterized by its shorter size, with sterile fronds that grow up to a maximum height of 30-40 cm. Despite that, even if infrequent, some specimens can have sterile fronds up to 1 m long. The species also present coriaceous, stiff, and linear pinnae, and it is common to find specimens lacking costal scales. After herborized, the sterile blades often display a light green coloration.

Our analyses reveal that the specimens identified by Sehnem (1968) as B. regnellianum are, in fact, P. brasiliense. Moreover, the species B. simile he described is a synonym of P. regnellianum (Sehnem, 1968). Additionally, the specimen (Sehnem 6453, PACA) identified by Sehnem (1968) as a paratype from a different locality likely represents another species, most likely P. cordatum.

Distribution and habitat. There are records of the species for Bolivia, Brazil, Colombia, and Paraguay. In Brazil, it can be found in the South (Rio Grande do Sul, Santa Catarina, and Paraná), Southeast (Rio de Janeiro, São Paulo, Espírito Santo, and Minas Gerais), and Midwest (Goiás and Distrito Federal) regions. The species is a heliophyte, associated with well-lit environments, and wet soils. It is usually found in open environments, such as natural fields, forest edges, and trails, but also inside forests. Moreover, this species can grow directly on rocks, or in rock crevices, and inhabits Restingas, being directly exposed to the sea. Also, there are records of this species as an accidental epiphyte. Parablechnum regnellianum can be found between 10 and 1900 m a.s.l., with a record of a sample growing at 2350 m in Medellín, Colombia (Posada 164). It habits Tropical and Subtropical Grasslands, Savannas, and Shrublands from Brazil and Paraguay, and Tropical and Subtropical Moist Broadleaf Forests from Brazil, Colombia, and Bolivia.

Specimens Examined. Bolivia. SANTA CRUZ: Santa Cruz de la Sierra, Near bottom of valley of Quebrada Guapurucillo, 18° 12’S, 63° 43’ 12” W, 16 February 1998, M. H. Nee 48370 (NY). Brazil. DISTRITO FEDERAL: Brasília, Córrego Cabeça de Veado, 15° 46’ 47” S, 47° 55’ 47” W, 05 July 1999, C. E. Rodrigues Jr. s.n. (UB); idem, Fazenda Água Limpa, 15° 46’ 47” S, 47° 55’ 47” W, 04 October 2000, C. Polcheira s.n. (UB); idem, 15° 47’ 30” S, 47° 52’ 50” W, 19 February 1966, H. S. Irwin s.n. (RB); idem, Fazenda Agua Limpa, 15° 46’ 26” S, 47° 47’ 42” W, 12 September 1982, J. A. Ratter 4766 (K). ESPÍRITO SANTO: Castelo, Parque Estadual do Forno Grande, 20° 30’ 58” S, 41° 05’ 01” W, 12 February 2008, P. H. Labiak 4556 (MBML, RB); Marechal Floriano, Sítio Almir Bressan, 20° 24’ 46” S, 40° 40’ 59” W, 4 January 1995, G. M. F. Viégas 266(VIES). GOIÁS: Chapada dos Veadeiros, 15° 56’ 04” S, 50° 08’ 25” W, 23 November 1997, L. Paulino s.n. (UB); Luziânia, Hidrelétrica de Corumbá III, 16° 35’ 47” S, 47° 59’ 48” W, 10 December 2007, C. H. G. Cezare 505 (UB); Silvânia, 16° 38’ 12” S, 48° 38’ 51” W, 06 December 2013, M. A. M. Elias 62 (UFG). MINAS GERAIS: 10 Feb 1846, A. F. Regnell,#I 490 (B!, BM!, S!, US!). Região da Represa de Furnas, Trilha da Cachoeira Feixo da Serra., 20° 35’ 44” S, 46° 13’ 54” W, 15 February 2006, A. A. Arantes 1672 (HUFU); idem, Estrada para Cachoeira Feixo da Serra, 46° 13’ 51” S, 20° 36’ 16” W, 15 February 2006, A. A. Arantes 1627 (HUFU); Estação Experimental, 21° 35’ 03” S, 43° 15’ 36” W, 19 May 1944, E. P. Heringer 1263 (RB); Paraíso Perdido, Córrego Quebra Anzol, 46° 19’ 24” S, 20° 37’ 28” W, 29 September 2005, R. Romero 7217 (HUFU); Belo Horizonte, Serra do Curral, 19° 55’ 15” S, 43° 56’ 16” W, 24 March 1945, L. O. Williams 6365 (IAN); Bocaina de Minas, Parque Nacional do Itatiaia, 22° 09’ 58” S, 44° 23’ 43” W, 16 June 2004, L. S. Sylvestre 1735 (RB); Caldas, Zona de amortecimento da Rebio Pedra Branca, 21° 57’ 17” S, 46° 23’ 26” W, 16 January 2014, E. A. Williams 249 (RB); Carangola, Morro da Torre, 20° 43’ 59” S, 42° 03’ 59” W, 23 June 1990, L. S. Leoni 1146 (RB); Datas, km286 on MG 259 road, 18° 26’ 36” S, 43° 39’ 25” W, 06 February 1972, W. R. Anderson 35577 (K); Juiz de Fora, Fazenda da Floresta, 43° 21’ 01” S, 21° 45’ 51” W, 13 August 1971, L. Krieger s.n. (SJRP n. 10707); idem, Colônia São Pedro, 43° 21’ 01” S, 21° 45’ 51” W, 11 April 1984, L. Krieger s.n. (SJRP n. 20637); idem, Jardim Botânico da Universidade Federal de Juiz de Fora, 21° 43’ 52” S, 43° 22’ 16” W, 09 January 2015, L.V. Lima 109 (HSTM); Ouro Preto, Parque Estadual do Itacolomi, 20° 26’ 30” S, 43° 30’ 49” W, 23 March 2004, C. Mynssen 554 (RB); Poços de Caldas, Mata do Cristo, Serra da Mantiqueira, 46° 33’ 41” S, 21° 47’ 16” W, 02 November 1999, F. R. Borges s.n. (SJRP); São João del Rei, Serra do Lenheiro, 21° 07’ 56” S, 44° 15’ 27” W, 30 May 1985, L. Krieger s.n. (SJRP n. 20385); Serra do Cipó, PARNA Serra do Cipó, 19° 24’ 57” S, 43° 34’ 22” W, 31 May 2007, M. Paciencia 2753 (UNIP). PARANÁ: April 1883, D. Parodi 81 (K); Arapoti, Rio das Cinzas, 24° 09’ 28” S, 49° 49’ 36” W, 28 November 1968, G. Hatschbach 20425 (MBM); Balsa Nova, Ponte dos Arcos, 25° 33’ 11” S, 49° 48’ 19” W, 23 March 2005, C. Kozera 2004 (MBM); Castro, 24° 47’ 28” S, 50° 00’ 43” W, January 1980, L. T. Dombrowski 13317 (MBM); Jaguariaíva, Repouso número II, 49° 42’ 21” S, 24° 15’ 04” W, 26 April 1991, L. Amorin 52 (SJRP); idem, Fazenda Jardim do Trigo, 49° 42’ 21” S, 24° 15’ 04” W, 10 November 1989, M. F. Morel 23 (SJRP); Lapa, Volta Grande, 25° 46’ 11” S, 49° 42’ 57” W, 02 March 1982, G. Hatschbach 44906 (MBM, UCS); Ortigueira, UHE Mauá, 24° 06’ 41” S, 50° 43’ 24” W, 13 November 2012, C. Michelon 1573 (MBM); Palmeira, BR277, km 156, 25° 25’ 46” S, 50° 00’ 23” W, 20 April 2000, E. Barboza 471 (MBM); idem, Fazenda Santa Rita, 25° 25’ 46” S, 50° 00’ 23” W, 28 January 1981, L. T. Dombrowski13066 (MBM); idem, Rio dos Papagaios, 25° 25’ 46” S, 50° 00’ 23” W, 20 April 2008, M. G. Caxambú 2165 (MBM); Piraí do Sul, 24° 31’ 34” S, 49° 56’ 55” W, 30 April 2012, B. K. Canestraro 352 (MBM); Ponta Grossa, UHE Pitangui, 25° 05’ 42” S, 50° 09’ 43” W, 18 February 2012, B. K. Canestraro 302 (MBM); idem, Nascente do rio Tibagi, 25° 05’ 42” S, 50° 09’ 43” W, 23 March 2009, B. O. Andrade 303 (MBM); idem, 25° 05’ 42” S, 50° 09’ 43” W, 20 December 1971, L. Krieger s.n. (UPCB n. 11308); idem, Parque Estadual de Vila Velha, 25° 13’ 59” S, 50°W, 19 December 2004, P. B. Schwartsburd 504 (MBM, RB); Porto Amazonas, Fazenda São Luís, 25° 32’ 41” S, 49° 53’ 25” W, 22 December 1963, G. Hatschbach 10793 (MBM); Porto Amazonas, Lajeado, 25° 32’ 41” S, 49° 53’ 25” W, 12 June 2001, O. S. Ribas 3614 (ALCB, MBM, UCS); Quatro Barras, Serra da Baitaca, Morro Anhangava, 25° 21’ 56” S, 49° 04’ 37” W, 13 March 1997, J. Cordeiro 1407 (MBM); Tibagi, Rodovia do Café, Rio Capivari, 24° 30’ 34” S, 50° 24’ 49” W, 11 February 1976, G. Hatschbach 38077 (MBM). RIO DE JANEIRO: Guapimirim, Parque Nacional da Serra dos Órgãos, 22° 31’ 19” S, 42° 58’ 44” W, 22 January 1994, J. M. A. Braga 988 (RB). RIO GRANDE DO SUL: Aparados da Serra, Passo da Guarda, 16 Jan 1952, Sehnem 5861 (PACA!). Bom Jesus, Arroio do Fundo do Cilho, 28° 40’ 25” S, 50° 26’ 23” W, 09 January 2005, R. Wasum 2393a (UCS); Caxias do Sul, Jardim Botânico, 29° 08’ 20” S, 51° 09’ 19” W, 26 August 2006, P. Rabelo 30 (UCS); Osório, Lago do Rincão, 29° 54’ 15” S, 50° 13’ 03” W, 22 January 2015, F. Gonzatti 1570 (UCS); Rio Grande, Estrada do Cassino, 32° 06’ 04” S, 52° 10’ 09” W, 25 May 2014, F. Gonzatti 1249a (UCS). Timbé São Francisco de Paula, 16 Nov. 1953, Sehnem 6452 (PACA!, MBM!). SANTA CATARINA: Água Doce, 26° 41’ 57” S, 51° 36’ 06” W, 23 March 2018, A. Kassner-Filho 2479 (FURB); Florianópolis, Trilha Praia Matadeiro/Lagoinha do Leste, Parque Nacional de São Joaquim, 27° 46’ 01” S, 48° 28’ 43” W, 07 January 2021, A. L. Gasper 783 (FURB); idem, Lagoinha do Leste, 27° 45’ 59” S, 48° 28’ 43” W, 16 November 2019, L. A. Funez9195 (FURB); idem, Trilha Praia Matadeiro/Lagoinha do Leste, 27° 45’ 52” S, 48° 28’ 42” W, 24 February 2019, N. P. Smith 648 (FURB); Lages, Morro do Pinheiro Seco, 27° 48’ 58” S, 50° 19’ 34” W, 14 April 1963, R. Reitz 14891 (MBM); São José do Cerrito, Faxinal dos Ferreiras, 27° 37’ 55” S, 50° 34’ 43” W, 10 April 2019, A. Kassner-Filho 5064 (FURB). SÃO PAULO: Campos do Jordão, 22° 44’ 05” S, 45° 35’ 23” W, 5 February 1937, P. Campos Porto 3078 (RB); Ipiranga, 25º 01’ 17” S, 50° 35’ 24” W, Jun 1912, H. Luederwaldt 21703 (BM!, US!, S!, B!). São José do Barreiro, Serra da Bocaina, Parque Nacional, 22° 44’ 02” S, 44° 37’ 00” W, 29 April 2018, F. Gonzatti 4327 (UCS); São José do Barreiro, Parque Nacional da Serra da Bocaina, 22° 44’ 31” S, 44° 37’ 00” W, 06 January 2008, P. H. Labiak 4287 (UPCB); São Pedro, Vicinal entre os municípios São Pedro e Charqueada, 47° 54’ 36” S, 22° 32’ 24” W, 12 May 2000, D. F. Peralta 850 (SJRP). Colombia. 2° 30’ 00”N, 76° 06’ 26” W, 1960, F. C. Lehmann 4422 (US). ANTIOQUIA: Medellín, Parque Ecologico Piedras Brancas, 6° 18’N, 75° 28’ 59” W, 21 May 1996, J. A. Posada 164 (MBM). Paraguay. CORDILLERA: Piribebuy, Desvio del la ruta 2 para el ramal Piribebuy-Paraguari, 25° 29’ 38” S, 56° 57’ 30” W, 21 July 1995, M. R. Pietrobom da Silva 2130 (SJRP).

Parablechnum usterianum (Christ) Gasper & Salino, Phytotaxa 275: 217. 2016. Lomaria usteriana Christ, Fl. Umgebung São Paulo 135. 1911. Blechnum usterianum (Christ) C.Chr., Index Filicum, Supplementum 1: 88. 1917. Type: Brazil. São Paulo, São Paulo, Ipiranga, June 1912, H. Luederwaldt s.n. (neotype [designated by Dittrich et al., 2018]: SPF94516!, isoneotype: BM000787908!).

Blechnum capense var. limosa Rosenst., Hedwigia 56: 362. 1915. Type: Brazil. São Paulo, Mooca, 09 February 1913, A.C. Brade 5821 (holotype: S05-10153!, isotype: HB3871).

Plants terrestrial; rhizomes erect or long-creeping, dark, ascending, at the apex with abundant, narrowly triangular scales with a prolonged apex, light castaneous, 2.9-13.4 × 0.5-2.5 mm at the base, margin entire or denticulate; fronds dimorphic, the sterile 46-96 cm long shorter than the fertile (63-120 cm long); petiole stramineous to dark brown on most of the length, dark brown to nigrescent near the base, sterile fronds 22-59 cm long, 2-5 mm diam., scaly throughout or only near the base, the scales similar to those of rhizome but smaller; of fertile fronds 39-79 cm long; sterile blades 20-36 × 9-26 cm, coriaceous, pinnate, oblong, terminal pinna conform; fertile blades 20-50 × 5-11 cm, ovate-lanceolate or oblong-lanceolate; rachises scaly, the scales light brown, concolorous, 0.7-4.4 × 0.2-1.2 mm at the base, linear to lanceolate, margins predominantly entire, with none to regular denticles, but with elongated projections; aerophores absent; sterile pinnae 9-18 pairs, 5-12 × 0.9-1.2 cm, slightly to strongly ascending, petiolulate or sessile (the basal ones petiolulate, sessile towards the apex), the apical ones adnate on the basiscopic side, pinnae narrowly oblong to nearly linear, margins crispate to entire at the base, serrate towards the apex or throughout, clearly revolute, apices cuneate, with a hyaline margin surrounding the pinnae, on the abaxial costa with lanceolate to triangular, twisted scales, light brown to whitish, margins denticulate; fertile pinnae 8-18 pairs, 7-18 × 0.3-0.4 cm, linear, without green tissue beyond the indusium; veins free, simple or once forked, with thickened tips at the margin; indusium linear, strongly and irregularly lacerate at the edges; spores monolete, equatorial diameter 36-55 µm, polar diameter 35-54 µm; perine with small cristae (3-6 µm high), small to large areolae (5-30 µm long), and covered with filaments.

Notes. There is a common confusion between Parablechnum usterianum and P. cordatum in exsiccates. Although P. usterianum usually presents a long-creeping rhizome, and P. cordatum presents a short-creeping rhizome, both can also display erect or/and robust rhizomes. This similarity can lead to confusion during identification, making it an unreliable characteristic to differentiate both species. Additionally, the rhizome is often absent in herbarium samples.

On the other hand, the pinnae can serve as a useful resource for species differentiation. Parablechnum usterianum is characterized by straight and often strongly ascending pinnae that compared to other species of the complex, are longer, narrower, and almost linear in shape, with a distinctive wedge-shaped apex. Furthermore, the pinnae are thick, stiff, coriaceous, and present revolute margins, which are rarely observed in the other three species. Sehnem (1968) treats this species as B. raddianum (= P. brasiliense) and characterizes it by its pinnae form which he refers to as “linear-ligulate”.

Distribution and habitat. The species is endemic to Brazil, occurring in the Southeast (Minas Gerais, São Paulo, and Rio de Janeiro) and South (Rio Grande do Sul, Santa Catarina, and Paraná) regions. It can be found between 5 and 1725 m a.s.l. and usually thrives in swampy or moist places associated with bodies of water and great sunlight incidence. Parablechnum usterianum predominantly occupies areas of the Tropical and Subtropical Moist Broadleaf Forests but can also occur in the transitional areas of the Tropical and Subtropical Grasslands, Savannas, and Shrublands.

Specimens Examined. Brazil. MINAS GERAIS: Aiuruoca, Rio Aiuruoca, 21° 58’ 32” S, 44° 36’ 11” W, 13 March 1989, A. Salino 660 (UEC); Delfim Moreira, Fazenda da Onça, 22° 36’ 34” S, 45° 20’ 51” W, 15 March 2011, L. L. Giacomin 1358 (BHCB); Santana do Riacho, PARNA da Serra do Cipó, 15 February 2007, M. Paciencia 2674 (UNIP). PARANÁ: Curitiba, Estrada para Rio Negro, 25° 25’ 40” S, 49° 16’ 23” W, 1952, G. Tessmann s.n. (MBM); idem, Parque Municipal Tingui, 25° 25’ 40” S, 49° 16’ 23” W, 14 April 2007, P. B. Schwartsburd 1337 (UPCB); General Carneiro, Fazenda do Pizzato, Lagoa Curicaca, 26° 25’ 39” S, 51° 18’ 56” W, 06 March 2006, A. C. Cervi8837 (UPCB); Ponta Grossa, Parque Estadual de Vila Velha, 25° 05’ 42” S, 50° 09’ 43” W, 19 October 2005, E. L. M. Assis 688 (COR); idem, Parque Estadual de Vila Velha, Estrada para Lagoa Dourada, 25° 05’ 42” S, 50° 09’ 43” W, 18 December 2004, P. B. Schwartsburd 471 (MBM); idem, Parque Estadual de Vila Velha, 25° 13’ 59” S, 50°W, 23 April 2005, P. B. Schwartsburd746 (NY); São Mateus do Sul, Fazenda do Durgo, 25° 52’ 27” S, 50° 22’ 58” W, 26 February 1987, R. M. Britez 1372 (MBM); idem, Fazenda do Durgo, 25° 52’ 27” S, 50° 22’ 58” W, 26 February 1987, R. M. Britez1372 (UPCB, MBM); Tijucas do Sul, APA de Guaratuba, 25° 55’ 41” S, 49° 11’ 56” W, 21 March 2013, V. Daniel 139 (MBM). RIO DE JANEIRO: Rio de Janeiro, 22° 54’ 30” S, 43° 12’ 24” W, s.d., Glaziou 7941 (K). RIO GRANDE DO SUL: Capão da Canoa, Estrada do Pontal, 29° 46’ 32” S, 50° 08’ 48” W, 26 August 2001, F. P. F. Athayde 1041 (SJRP); Cidreira, Fazenda Azaléia., 30° 10’ 52” S, 50° 12’ 20” W, 19 July 2012, F. Gonzatti 540 (FURB, VIES); Mostardas, Balneário Mostardense, 31° 06’ 41” S, 50° 51’ 55” W, 06 October 2013, F. Gonzatti 895 (UCS); Santa Vitória do Palmar, 33° 39’ 23” S, 53° 16’ 24” W, 16 March 2014, F. Gonzatti 1061 (FURB); Terra de Areia, 29° 36’ 31” S, 50° 04’ 23” W, 08 September 2013, F. Gonzatti 798 (UCS). SANTA CATARINA: Águas Mornas, rio Cubatão, 27° 48’ 35” S, 48° 57’ 39” W, 23 June 2010, A. Stival-Santos 3113 (FURB); Campo Alegre, Fazenda Sequóia, km107, 26° 10’ 49” S, 49° 11’ 47” W, 28 April 2008,R. G. Koehler s.n. (FURB); idem, Morro do Iquererim, Rio Negro, 26° 11’ 36” S, 49° 16’ 26” W, 15 March 1991, W. Oliveira 77 (SJRP); Frei Rogério, Núcleo Tritícola, 27° 10’ 48” S, 50° 45’ 36” W, 18 May 2011, A. Korte 6903 (FURB); Garopaba, Praia Vermelha, 28° 06’ 42” S, 48° 38’ 02” W, 07 July 2018, A. Kassner-Filho 3031 (FURB); Garuva, Alto Quiriri, 26° 02’ 21” S, 48° 57’ 16” W, 05 May 2015, L. A. Funez 4302 (FURB); Paulo Lopes, Sertão do Campo/Parque Estadual da Serra do Tabuleiro, 27° 53’ 36” S, 48° 45’ 21” W, 10 June 2010, M. Verdi 4940 (CRI, FURB); Rio dos Cedros, Cachoeira Formosa, 26° 44’ 18” S, 49° 16’ 27” W, 04 February 2018, L. A. Funez 7122 (FURB); Santa Cecília, Campo do Areão, 26° 57’ 28” S, 50° 25’ 16” W, 20 April 1962,R. Reitz 12636 (FURB); São Bento do Sul, Rio Vermelho, 26° 16’ 48” S, 49° 19’ 12” W, 16 February 2011, A. Korte 5936 (FURB); idem, Serra Alta, 26° 16’ 48” S, 49° 21’ 47” W, 06 March 2016, P. Schwirkowski 1638 (FURB, RB). SÃO PAULO: Campos do Jordão, proximidades do Parque Estadual de Campos do Jordão, 22° 46’ 06” S, 45° 33’ 07” W, 02 April 2002, V. A. O. Dittrich 1104 (HRCB); Jundiaí, Rebio Municipal da Serra do Japi, 25° 39’ 42” S, 46° 27’ 56” W, April 2009, J. A. Lombardi 6772 (HRCB); São Paulo, Parque Estadual da Serra do Mar, Núcleo de Curucutu, 23° 59’ 38” S, 46° 46’ 31” W, 13 May 2001, A. Salino 6544 (BHCB).

Discussion

The species analyzed here present high morphological plasticity, which could be considered an evolutionary strategy in plants to adapt to different environments (Mizutani & Kanaoka, 2018) since they are distributed throughout very distinct biomes and ecoregions, variable latitudes, and habitats. This morphological variability is mainly associated with their frond sizes, number of pinnae, rhizome form, and petiole coloration. Despite their morphological plasticity, the discussion of this clade as a species complex dates decades (Tryon & Tryon, 1982; Tryon & Stolze, 1993; Smith, 1995; Rolleri & Prada, 2006; Prada et al., 2008; Smith & Kessler, 2018; Wal et al., 2021) and supported by molecular analyses that recovered P. cordatum samples in different clades (Gasper unpubl. res.).

In our analysis, we examined the spores of type specimens of the complex, leading to a more precise understanding of its taxa. Parablechnum cordatum spores have been analyzed in several studies (Prada et al., 2008; Ramos Giacosa et al., 2009; Passarelli et al., 2010; Moran et al., 2018; Silva et al., 2019; Wal et al., 2021), although none of them analyzed type material. These studies diverge in spores’ characteristics in the individuals analyzed, indicating that what they analyzed were, in fact, different species. For example, Moran et al. (2018) have stated that the presence of filaments in spores is a synapomorphy of the Parablechnum genus, which no other genus of Blechnaceae possesses. They described P. cordatum spores with dense filaments covering the perine, the same as Prada (2008), Ramos Giacosa et al. (2009), and Passarelli et al. (2010). Conversely, Silva et al. (2019) and Wal et al. (2021) analyzed spores with discreet or no filaments. The spores of the P. cordatum complex may also be characterized by a folded perine, forming cristate ornamentation of variable lengths (Moran et al., 2018; Silva et al., 2019; Silva et al., 2021).

The perine ornamentation has already been determined as the bearer of greater variability in spores at the species level in Blechnaceae (Ramos Giacosa et al., 2009), although some species may present very similar ornamentation (Passarelli et al., 2010; Moran et al., 2018). In our analysis, we found spores that have both dense (such as P. brasiliense, P. regnellianum, and P. usterianum) and scarce filaments (P. cordatum). Moreover, we found differences in cristae thickness and areolae sizes in the specimens analyzed, indicating that we may be dealing with different species. The differences in spores’ perine ornamentation were followed by morphological variations mainly concerning the pinnae (Tab. 2), except for P. cordatum and P. brasiliense, in which the morphological differentiation is tenuous, and many characters overlap between them. Their spores, on the other hand, differ significantly in the density of filaments. Moran et al. (2018) stated that the differences in spores’ filaments are a distinguishing character among species; therefore, we can assume that these previously mentioned species are different.

The cristae thickness presented a considerable effect size, meaning that distinguishing species using this character can be practical and significant in most cases, except for the distinction between P. regnellianum versus P. usterianum, and P. brasiliense versus P. cordatum. On the other hand, the spores’ equatorial and polar diameters presented a small effect size, indicating that the use of spores’ size is limited for practical applications in this case. This also suggests that there are no cases of polyploidy within the complex, as differences in spores’ size between closely related species may be an indication of ploidy since genome size determines spores’ size (Barrington et al., 2020).

Using spores and pinnae characteristics we were able to delimitate the cryptic species that comprise the P. cordatum complex in Brazil. We showed that what was considered a species with high morphological plasticity can now be considered three distinct species: P. cordatum, P. brasiliense, and P. regnellianum. Additionally, we delimitated with better precision the species P. usterianum to enlighten its circumscription, given that this taxon can be often found in herbaria identified as P. cordatum, and vice versa.

Spores’ perine ornamentation is an effective qualitative feature that allows the distinction among the analyzed cryptic species, while certain morphological characteristics might assist in species identification. However, due to limited morphological differentiation, in some cases, the delimitation of the species will be possible only through spore analysis. Detecting and segregating cryptic species is essential for accurately estimating biodiversity. Treating these species as synonyms in an attempt to avoid misidentification can potentially impact biodiversity conservation by treating distinct taxa as a single entity (Carvalho et al., 2007).

Acknowledgments

GMOM and ALG thank the Fundação de Amparo à Pesquisa e Inovação de Santa Catarina (Fapesc), and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) - Finance Code 001, for granted scholarships and financing . ALG thanks CNPq for the productivity grant (311303/2020-0). Published with the approval of the Graduate Program in Biodiversity as Scientific Paper No 03. We thank the anonymous reviewers for their comments and contributions.

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• Data availability
  All the data supporting the results of this study have been made available on SciELO Data and can be accessed at DOI: https://doi.org/10.48331/scielodata.VUNVYA.

Supplementary Material

The following online material is available for this article:

Table S1. Georeferenced data from analyzed specimens in this study.

Figure S1. Exsiccates and spores seen under SEM of type individuals analyzed. A, B. Parablechnum cordatum (J. Dombey s.n., P00307042, lectotype, and BM000769804, respectively). C, D. Blechnum macahense (A.C Brade 15801, HB38760, lectotype; synonym of Parablechnum cordatum). E, F. Parablechnum regnellianum (I. Regnell 490, B 20 0033168, lectotype). Scale bars = 20 µm (B, D, F).

Figure S2. Exsiccates and spores seen under SEM of type individuals analyzed. A, B. Parablechnum brasiliense (G. Raddi s.n, PI010198, isotype). C, D. Blechnum itatiaiense (A.C. Brade 10115, RB00543238, isolectotype; synonym of Parablechnum brasiliense). E, F. Blechnum simile (A. Sehnem6452, MBM106456, paratype, synonym of Parablechnum regnellianum). Scale bars = 20 µm (B, D, F).

Figure S3. Exsiccate and spore seen under SEM of type individuals analyzed. A, B. Parablechnum usterianum (H. Luederwaldt 21703, BM000787908, isoneotype). Scale bar = 20 µm (B).

Appendix

Appendix S1. List of specimens in which spores were analyzed under light microscopy (LM) and in scanning electron microscope (SEM). Specimens signalized with “*” after herbaria abbreviation were analyzed only in SEM; with “**” were analyzed only in LM.

Parablechnum brasiliense: - Brazil. - Minas Gerais: Bocaina de Minas, Parque Nacional do Itatiaia, 22° 09’ 58”S, 44° 23’ 43”W, 16 June 2004, L. S. Sylvestre 1735 (RB); Carangola, 20° 42’ 59”S, 42° 28’ 59”W, June 1988, L. S. Leoni 694 (RB**); São Sebastião de Paraíso, 20° 54’ 38”S, 46° 59’ 10”W, 24 May 1945, A. C. Brade 17969 (RB**). Paraná: Campos do Jordão, Horto Florestal, 22° 43’ 58”S, 45° 35’ 24”W, 1 June 1984, A. Santos 234 (RB); Jaguariaíva, Vale do Codó, 24° 16’ 06”S, 49° 43’ 04”W, 13 July 2005, E. Barboza 1084 (MBM); idem, Parque Estadual do Cerrado, 24° 10’ 00”S, 49° 39’W, 28 August 1993, P. H. Labiak 51 (UPCB). Rio de Janeiro: Itatiaia, 22° 26’ 43”S, 44° 35’ 18”W, 22 Jun 1930, Brade 10115 (RB!*, BM!*); Teresópolis, Parque Nacional da Serra dos Órgãos, 22° 12’ 17”S, 42° 53’ 51”W, 24 Ferbuary 2005, R. A. Engelmann 243 (RB); Tijuca, without date, G. Raddi s.n. (PI!*). Santa Catarina: Bom Jardim da Serra, Morro da Igreja, 28° 07’ 24”S, 49° 28’ 48”W, 8 April 2010, A. Salino 14750 (FURB); Orleans, Trilha Pedra Furada, 28° 08’ 02”S, 49° 28’ 45”W, 11 March 2018, A. Kassner-Filho 2599 (FURB); São Bento do Sul, CEPA, 26° 19’ 25”S, 49° 18’ 26”W, 30 March 2007, A. L. Gasper 94 (FURB); idem, Sertãozinho, 26° 19’ 02”S, 49° 24’ 22”W, 23 October 2016, P. Schwirkowski 1990 (FURB); Serro, Estrada entre Milho Verde e São Gonçalo do Rio das Pedras, 18° 26’ 25”S, 43° 29’ 06”W, 10 April 2011, A. L. Gasper 2846 (FURB); Urubici, Corvo Branco, 28° 03’ 16”S, 49° 22’ 07”W, 10 September 2019, A. L. Gasper 540 (FURB). São Paulo: Campos do Jordão, Horto Florestal, 22° 43’ 58”S, 45° 35’ 24”W, 1 June 1984, A. Santos 234 (RB).

Parablechnum cordatum: - Brazil. - Rio de Janeiro: Macaé, Estrada do Rio Frade de Macaé, 19 Feb 1937, Brade 15801 (HB!*). Santa Catarina: Apiúna, Faxinalzinho, 27° 10’ 49”S, 49° 23’ 37”W, 17 March 2010, A. Korte 2160 (FURB); Bluemanau, Parque Nacional da Serra do Itajaí, 27° 03’ 24”S, 49° 05’ 16”W, 22 March 2007, A. L. Gasper 664 (FURB*); idem, Parque Nacional da Serra do Itajaí, 27° 03’ 24”S, 49° 05’ 16”W, 17 August 2007, A. L. Gasper 572 (FURB); Massaranduba, Serra do Jacu, 26° 33’ 01”S, 49° 03’ 02”W, 4 February 2011, A. Korte 5908 (FURB); Nova Trento, Rio Veado, 27° 21’ 38”S, 49° 08’ 13”W, 29 September 2010, A. Korte 4532 (FURB*). - Peru. - Concepción: J. Dombey, s.n. (BM!*).

Parablechnum regnellianum: - Brazil. - Espírito Santos: Castelo, Parque Estadual do Forno Grande, 20° 30’ 58”S, 41° 05’ 01”W, 12 February 2008, P. H. Labiak 4556 (RB*). Minas Gerais: 10 Feb 1846, A. F. Regnell, #I 490 (B!*); Caldas, Zona de amortecimento da Rebio Pedra Branca, 21° 57’ 17”S, 46° 23’ 26”W, 16 January 2014, E. A. Williams 249 (RB**). Paraná: Campos do Jordão, 22° 44’ 05”S, 45° 35’ 23”W, 5 Ferbuary 1937, P. Campos Porto 3078 (RB); Lapa, Volta Grande, 25° 46’ 11”S, 49° 42’ 57”W, 02 March 1982, G. Hatschbach 44906 (MBM**); Palmeira, Fazenda Santa Rita, 25° 25’ 46”S, 50° 00’ 23”W, 28 January 1981, L. T. Dombrowski 13066 (MBM); idem, Rio dos Papagaios, 25° 25’ 46”S, 50° 00’ 23”W, 20 April 2008, M. G. Caxambú 2165 (MBM); Piraí do Sul, 24° 31’ 34”S, 49° 56’ 55”W, 30 April 2012, B. K. Canestraro 352 (MBM); Ponta Grossa, Nascente do rio Tibagi, 25° 05’ 42”S, 50° 09’ 43”W, 23 March 2009, B. O. Andrade 303 (MBM); idem, Parque Estadual de Vila Velha, 25° 13’ 59”S, 50°W, 19 December 2004, P. B. Schwartsburd 504 (MBM**, RB**); Porto Amazonas, Fazenda São Luís, 25° 32’ 41”S, 49° 53’ 25”W, 22 December 1963, G. Hatschbach 10793 (MBM**); idem, Lajeado, 25° 32’ 41”S, 49° 53’ 25”W, 12 June 2001, O. S. Ribas 3614 (ALCB, MBM, UCS). Rio de Janeiro: Guapimirim, Parque Nacional da Serra dos Órgãos, 22° 31’ 19”S, 42° 58’ 44”W, 22 January 1994, J. M. A. Braga 988 (RB). Rio Grande do Sul: Rio Grande, Estrada do Cassino, 32° 06’ 04”S, 52° 10’ 09”W, 25 May 2014, F. Gonzatti 1249a (UCS); Timbé São Francisco de Paula, 16 Nov. 1953, Sehnem 6452 (MBM!*). Santa Catarina: Florianópolis, Trilha Praia Matadeiro/Lagoinha do Leste, Parque Nacional de São Joaquim, 27° 46’ 01”S, 48° 28’ 43”W, 07 January 2021, A. L. Gasper 783 (FURB); idem, Trilha Praia Matadeiro/Lagoinha do Leste, 27° 45’ 52”S, 48° 28’ 42”W, 24 February 2019, N. P. Smith 648 (FURB). São Paulo: Campos do Jordão, 22° 44’ 05”S, 45° 35’ 23”W, 5 Ferbuary 1937, P. Campos Porto 3078 (RB); Ipiranga, 25º 01’ 17”S, 50° 35’ 24”W, Jun 1912, H. Luederwaldt 21703 (BM!*); São José do Barreiro, Parque Nacional da Serra da Bocaina, 22° 44’ 31”S, 44° 37’ 00”W, 06 January 2008, P. H. Labiak 4287 (UPCB).

Parablechnum usterianum: - Brazil. - Paraná: General Carneiro, Fazenda do Pizzato, Lagoa Curicaca, 26° 25’ 39”S, 51° 18’ 56”W, 06 March 2006, A. C. Cervi 8837 (UPCB**). Rio Grande do Sul: Mostardas, Balneário Mostardense, 31° 06’ 41”S, 50° 51’ 55”W, 06 October 2013, F. Gonzatti 895 (UCS). Santa Catarina: Garopaba, Praia Vermelha, 28° 06’ 42”S, 48° 38’ 02”W, 07 July 2018, A. Kassner-Filho 3031 (FURB); Garuva, Alto Quiriri, 26° 02’ 21”S, 48° 57’ 16”W, 05 May 2015, L. A. Funez 4302 (FURB); São Bento do Sul, Rio Vermelho, 26° 16’ 48”S, 49° 19’ 12”W, 16 February 2011, A. Korte 5936 (FURB).

Edited by

• Editor-in-Chief:
  Thaís Elias Almeida

• Associate Editor:
  Alexandre Salino

Data availability

All the data supporting the results of this study have been made available on SciELO Data and can be accessed at DOI: https://doi.org/10.48331/scielodata.VUNVYA.

Publication Dates

• Publication in this collection
  02 Dec 2024
• Date of issue
  2024

History

• Received
  17 Oct 2023
• Accepted
  22 July 2024