The morpho-anatomy of roots, stems, scapes and leaves of Blastocaulon albidum, B. prostratum and B. scirpeum was studied. All species occur in campos rupestres of Minas Gerais, central Brazil. They possess very fine roots with a uniseriate epidermis, two-three layers of parenchymatous cells in the cortex, and a vascular tissue with few elements. The stem of B. albidum and B. prostratum are aerious and branched while in B. scirpeum some individuals have rhizoma or very short stems. They have epidermis, cortex and a vascular cylinder. The leaves are delicate, with thin-walled epidermal cells, loosely aggregated chlorophyll parenchyma and a reduced number of vascular bundles. The scapes are cylindrical, slender, without ribs and only have four collateral vascular bundles. These characteristics which distinguish Blastocaulon from Paepalanthus, are typical of plants growing in damp shady habitats, the environment where most Blastocaulon species are found.
morphology; anatomy; Blastocaulon