A look at endemic manihot species for northeastern Brazil: Taxonomy, richness, distribution and conservation

ABSTRACT

Manihot includes about 150 species with a Neotropical distribution. Wild species of Manihot constitute a plant genetic heritage that can be used in breeding programs for the cultivable species Manihot esculenta Crantz (cassava). However, wild populations, especially endemic ones, are under constant threat due to habitat destruction and climate change. The objective of this manuscript was to elaborate a taxonomic treatment of the endemic species of Manihot recorded in Northeast Brazil; determine the geographical distribution of species, richness, their conservation status, and solve typification problems. The study was based on the analysis of specimens deposited in national and international herbaria, as well as on field observations. Fifteen endemic species of Manihot were found, we propose lectotypes for five of them and one neotype. Most species are distributed in the state of Bahia, growing in Caatinga, Cerrado, and Atlantic Forest environments. Only M. breviloba was found in the states of Sergipe and Alagoas. The richest area was found in the Chapada Diamantina of the Espinhaço Range. In terms of conservation status, 80% of endemic species are in some threatened category, 13% are in the near threatened category and only 7% are in the least concern category.

Keywords:
Crotonoideae; Euphorbiaceae; Conservation status; Richness; Typification