A new combination and taxonomic notes in Pseudobombax Dugand (Malvaceae).

Taxonomic notes in the Neotropical genus Pseudobombax (Malvaceae) are presented. One new combination and two new heterotypic synonyms for taxa originally described from Brazil and Ecuador are proposed based on both morphological and previously published molecular evidence. The taxonomic changes will be adopted in a treatment of Pseudobombax for the upcoming Brazilian Flora 2020 and in a forthcoming revision of the genus throughout its range.

Revisiting the phylogeny of Bombacoideae (Malvaceae): Novel relationships, morphologically cohesive clades, and a new tribal classification based on multilocus phylogenetic analyses.

Bombacoideae (Malvaceae) is a clade of deciduous trees with a marked dominance in many forests, especially in the Neotropics. The historical lack of a well-resolved phylogenetic framework for Bombacoideae hinders studies in this ecologically important group. We reexamined phylogenetic relationships in this clade based on a matrix of 6465 nuclear (ETS, ITS) and plastid (matK, trnL-trnF, trnS-trnG) DNA characters. We used maximum parsimony, maximum likelihood, and Bayesian inference to infer relationships among 108 species (∼70% of the total number of known species). We analyzed the evolution of selected morphological traits: trunk or branch prickles, calyx shape, endocarp type, seed shape, and seed number per fruit, using ML reconstructions of their ancestral states to identify possible synapomorphies for major clades. Novel phylogenetic relationships emerged from our analyses, including three major lineages marked by fruit or seed traits: the winged-seed clade (Bernoullia, Gyranthera, and Huberodendron), the spongy endocarp clade (Adansonia, Aguiaria, Catostemma, Cavanillesia, and Scleronema), and the Kapok clade (Bombax, Ceiba, Eriotheca, Neobuchia, Pachira, Pseudobombax, Rhodognaphalon, and Spirotheca). The Kapok clade, the most diverse lineage of the subfamily, includes sister relationships (i) between Pseudobombax and "Pochota fendleri" a historically incertae sedis taxon, and (ii) between the Paleotropical genera Bombax and Rhodognaphalon, implying just two bombacoid dispersals to the Old World, the other one involving Adansonia. This new phylogenetic framework offers new insights and a promising avenue for further evolutionary studies. In view of this information, we present a new tribal classification of the subfamily, accompanied by an identification key.

Reinterpretation of the nomenclatural type of Pseudobombax heteromorphum (Malvaceae, Bombacoideae) reveals an overlooked new species from Bolivia.

In the course of a taxonomic revision of Pseudobombax Dugand, one of us (JGCS) frequently has observed herbarium specimens of Bombacoideae that comprise a mixture of different Angiosperm families. In particular, Pseudobombax heteromorphum (Kuntze) A. Robyns, a frequent name in checklists of the Bolivian flora, is based on type material of Bombax heteromorphum Kuntze that is clearly a mixture of Pseudobombax flowers and Tabebuia Gomes ex DC. (Bignoniaceae) leaves. We herein designate as the lectotype of Bombax heteromorphum the flowers of an herbarium sheet deposited in NY and as epitype a complete specimen (leaves, flowers, and fruit) in HUEFS. We consider Bombax heteromorphum to be a synonym of Pseudobombax longiflorum (Mart.) A. Robyns, a species widespread in Neotropical seasonally dry forest of Bolivia, Brazil, Paraguay, and Peru. Furthermore, we describe a new species, Pseudobombax pulchellum Carv.-Sobr., apparently endemic to seasonally dry tropical forest (SDTF) in Bolivia (Chiquitano dry forest), based on specimens commonly but incorrectly identified as Pseudobombax heteromorphum.We also comment on the morphology, distribution, and conservation status of this new species.

ResumenEn el curso de una revisión taxonómica de Pseudobombax Dugand, uno de nosotros (JGCS) con frecuencia se ha observado especímenes de herbario de Bombacoideae que comprenden una mezcla de diferentes familias de angiospermas. En particular, Pseudobombax heteromorphum (Kuntze) A.Robyns, un nombre frecuente en las listas de la flora boliviana, se basa en el material tipo de Bombax heteromorphum Kuntze que es claramente una mezcla de flores de Pseudobombax y hojas de Tabebuia Gomes ex DC. (Bignoniaceae). Aquí se designa como el lectotipo de Bombax heteromorphum las flores de uno espécimen de el herbario NY y como epitipo uno espécimen completo (hojas, flores y frutos) de el herbario HUEFS. Consideramos Bombax heteromorphum como sinónimo de Pseudobombax longiflorum (Mart.) A.Robyns, una especie ampliamente distribuida en los bosques neotropicales estacionalmente seco de Bolivia, Brasil, Paraguay y Perú. Por otra parte, se describe una especie nueva, Pseudobombax pulchellum Carv.-Sobr., aparentemente endémica de los Bosques secos Chiquitanos en Bolivia, con base en colecciones comúnmente, pero incorrectamente identificado, como Pseudobombax heteromorphum, con comentarios sobre su morfología, distribución y estado de conservación.