The anatomy of scapes leaves and bracts of twenty four taxa included in Syngonanthus sect. Eulepis (Bong. ex Koern.) Ruhland from the Brazilian "campos rupestres" was studied. Scapes present a vary number of ribs, thick-walled uniseriate epidermal cells, alternate sclerenchyma, and chlorenchyma in the cortex, continuous or discontinuous endodermis, star-shaped pericycle, collateral vascular bundles, and pith with thin or thick-walled cells. Leaves and bracts have total or partial thick-walled epidermal cells, stomata on the abaxial surface, margins with chlorenchyma or sclerenchyma under the epidermis, mesophyll with hypodermis formed by sclerenchyma or aqüiferous parenchyma, and collateral vascular bundles with a double sheath: the external one, the endodermis, and the internal one, the pericycle. Thick-walled cells and sclerenchyma in the scapes, leaves, and bracts present in the species of Syngonanthus sect. Eulepis are probably a response to the typical windy and bright environment of the "campos rupestres". Features such as thick-walled epidermal cells, non-specialized substomatal chamber, presence of hypodemis, sclerenchyma, and compact chlorenchyma are typical of the Syngonanthus sect. Eulepis species. These anatomical features could be used to define the taxa in the section.
Eriocaulaceae; anatomical features; Syngonanthus
