A morphological study of Marlierea Cambess. occurring in Amazonian Brazil was carried out in order to obtain a better understanding of the morphology and taxonomy of all species in the region and to provide data to elucidate the taxonomic segregation of Marlierea from the morphologically similar Myrcia DC. ex Guill. In Amazonian Brazil, Marlierea is represented by 11, primarily forest, species (Marlierea bipennis (O. Berg) McVaugh, M. caudata McVaugh, M. ensiformis McVaugh, M. ferruginea (Poir.) McVaugh, M. mcvaughii B. Holst, M. scytophylla Diels, M. spruceana O. Berg, M. subulata McVaugh, M. summa McVaugh, M. umbraticola (Kunth) O. Berg, and M. velutina McVaugh). The taxonomically problematic M. obumbrans (O. Berg) Nied. is discussed as a badly known species. The species are trees or shrubs with opposite leaves (sometimes alternate in M. velutina); inflorescences racemose or paniculate (in panicles, cymes, or dichasiums), sometimes in fasicles; flower buds generally closed; calyx lobes 4-5, opening irregularly; and petals frequently absent. The states of Amazonas and Pará are the most species-rich. Marlierea spruceana and M. umbraticola are the most common species. Additional studies of M. obumbrans, morphologically intermediate between Marlierea and Myrcia, will be untaken in the future in order to establish the correct taxonomic placement of this enigmatic species.
Myrtaceae; Marlierea; Taxonomy; Amazonia
