Anatomia do escapo floral de espécies brasileiras de Paepalanthus subgênero platycaulon (eriocaulaceae)

Abstract

The scape anatomy of 17 taxa of Paepalanthus subgenus Platycaylon were studied, being 10 taxa of sect. Divisi and seven of sect. Conferti. The study was carried out to see whether scape morphology and anatomy provide valid taxonomic characters at the subgeneric level in Paepalanthus and to lest a proposal to recognize two sections within Paepalanthus subgenus Platycaylon: sect. Divisi and sect. Conferti. The material for anatomical study was collected in Brazil, partly from herbarium specimens and partly from fresh material collected in the field, from the Serra do Cipó. Minas Gerais State. In this work, we observe that Paepalanthus subg. Platycaulon is characterized morphologically by its pluricapitulate scapes. Anatomycally, the studied species of the Divisi sect, are characterized by having separate vascular cylinders, and present cortical vascular bundles in Paepalanthus vellozioides and P. spixianus, being these characteristics unique to the family, while the scapes of the studied members of sect. Conferti display a continuous vascular cylinder, which is analogous with other groups within the Eriocaulaceac, and present pith vascular bundles in Paepalanthus itatiaiensis, P planifolius and P. paulensis, characteristics unique to the family.