Sano and P. subsect. Aphorocaulon R

Sano and P. subsect. Aphorocaulon Ruhland. The group composed of P. flaccidus (Bong.) Kunth, P. strictus Koern., and P. trichophyllus (Bong.) Koern., recently excluded from P. sect. Diphyomene (Trovó & Sano, 2010), also sometimes emerges related to Actinocephalus and P. subsect. Aphorocaulon, or to P. sect. Diphyomene. The different placements result
from the different molecular markers and taxa examined. Thus, the relationships between these groups are still unresolved and require further investigation.
Anatomical studies of representatives of Paepalanthus (Hensold, 1988; Splett et al., 1993; Scatena & Moraes, 1996; Scatena et al., 1998; Scatena & Rosa, 2001; Trovó et al.,2010) demonstrate the significance of anatomical characters to distinguish species, characterize subgeneric groups, and evaluate their relationships. Hensold (1988), when monographing P. subgen. Xeractis Koern., detailed the vegetative anatomy of most of the 27 species belonging to this subgenus. Splett et al. (1993) studied leaf anatomy of some Brazilian Eriocaulaceae in order to evaluate diagnostics characters for different groups. Scatena and Moraes (1996) investigated the vegetative anatomy of some taxa of P. subgen. Platycaulon Koern., confirming that leaf and scape anatomy can be used to segregate the species into two sections, as proposed by Ruhland (1903). Scatena & Rosa (2001) explored the vegetative anatomy of P. subsect. Aphorocaulon and concluded that
most of the anatomical features are shared with Actinocephalus. Trovó et al. (2010) detailed the anatomy and morphology of the inflorescences of P. sect. Diphyomene, in the context of supplying taxonomic and phylogenetic information for the entire group. Thus,the objective of the present study is to identify and describe anatomical structures of the bracts, leaves, and scapes of P. sect. Diphyomene and its close relatives in order to contribute to the systematics of the group.