Notes on morphology, taxonomy and geographic distribution of Apeiba (Malvaceae, Grewioideae) in the Brazilian Amazon

ABSTRACT Apeiba (Malvaceae, Grewioideae) is an important component of the Neotropical flora, but taxonomic knowledge of its species is limited, particularly within the Amazon region. This study aimed to provide an updated taxonomic treatment of Apeiba native to Brazil, with focus on Amazonian collections. Species of Apeiba are trees with large yellowish-white flowers with a very particular fruit, an indehiscent capsule, usually globose to slightly flattened, covered either by long and numerous bristles, or densely apiculate. We provide synoptic descriptions for each Amazonian Apeiba species from Brazil, and comments on relevant synonyms and designated lectotypes for three names. We also provide an identification key, a list of examined material and distribution data, including a list of new occurrence records for some Brazilian states. Illustrations and notes on taxonomy and nomenclature are also included when appropriate.