RESUMEN
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 (â¼70% 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.
Asunto(s)
Sitios Genéticos , Malvaceae/clasificación , Malvaceae/genética , Filogenia , Teorema de Bayes , Bases de Datos Genéticas , Malvaceae/anatomía & histología , Carácter Cuantitativo Heredable , Semillas/anatomía & histologíaRESUMEN
A new species of Eriotheca (Bombacoideae, Malvaceae) from montane wet forests in the Atlantic Forest of Bahia, northeastern Brazil, is described and illustrated. It is known from only three populations situated between 750 m and 850 m in elevation on mountain summits and categorized as Endangered (EN) based on IUCN criteria. Eriothecapaganuccii is distinct from all congeners by the combination of coriaceous to strongly coriaceous leaves and remarkable few-seeded, globose to subglobose woody capsules that contain scanty kapok and the largest seeds known in the genus to date. The affinities of E.paganuccii to morphologically similar species as well as the importance of obtaining phenologically complete collections are discussed.
RESUMEN
A new species of Eriotheca (Malvaceae, Bombacoideae) from coastal areas in the northeastern Brazilian states of Alagoas and Bahia is described and illustrated. Eriotheca alversonii inhabits Atlantic coastal forest and is found principally on sandy soils in restinga vegetation. It is most similar morphologically to E. parvifolia. Both species have 3-foliolate leaves and short petioles on fertile branches, but the new species has smaller flowers, truncate to crenulate calyces, and smaller globose to subglobose capsules. The affinities of E. alversonii to morphologically similar species and its phenology are discussed. A distribution map and preliminary assessment of its conservation status are provided.