Untangling the taxonomy and geographic distribution of Quararibea floribunda (Malvaceae: Malvoideae)

Quararibea floribunda, a species endemic to Brazil, is poorly studied
taxonomically, and little is known about its ecology and conservation
status. Since its publication in 1842, only a few studies have reported on
its morphological circumscription, thus remaining as a complex in the
taxonomy of Quararibea. In addition, little is known about its geographic
distribution, which, according to most authors, is restricted to the
Cerrado Biome, a phytogeographic biome of dry forests. Therefore, we
herein review and clarify the morphological circumscription and
distribution of Q. floribunda in different vegetation types, designate a
lectotype, and recognize its conservation status as Vulnerable (VU). The
present study is based on analysis of protologues and further pertinent
literature. Several herbaria were consulted, both in person and online.
Fieldwork was done between 2017 and 2020 in different locations of
midwestern and southeastern Brazil, mainly in dry forests of the Cerrado
Biome. We confirm that Q. floribunda also occurs in the Atlantic Forest
Biome and that it is not exclusive to the Cerrado Biome, as previously
thought. All known populations in this biome inhabit humid habitats, and
as such, they are closer to the vegetation of the Atlantic Forest Biome
than the typical Cerrado dry forests. In addition to assessing the
conservation status of Q. floribunda, we evaluate its nomenclatural
history, leading to the designation of a lectotype, finally highlighting
vegetative and floral diagnostic characters. A distribution map is
provided, as well as a morphological comparative analysis between species
with foliar domatia in extra-Amazonian Brazil.