The anatomical characteristics of vegetative organs and floral scape of Leiothrix crassiflora (Eriocaulaceae) were investigated due to their ecological and taxonomic implications for the species. L. crassiflora grows in recently decomposed stony, sandy soils of the Serra do Cipó area of the Espinhaço mountains range, state of Minas Gerais, Brazil. It is found both on wet and dry soils, exposed to constant winds, high light intensities and daily extreme fluctuations of temperature. The root presents a cortical parenchyma with two types of cells that form a lisigenous air parenchyma allowing the plant to survive in wet soils. The endodermis cells present thickened walls. The Casparian strips are shown only by very young roots. Details are given to special leaf substomatal chambers. They are an efficient protection for the gaseous exchange and considered as an important character of the Eriocaulaceae.
anatomy; Leiothrix crassifolia; rupestrian field; Eriocaulaceae