Anatomia comparada dos órgãos do sistema vegetativo de três espécies de Encyclia (Orchidaceae: Epidendroideae)

Abstract

Encyclia comprises 150 species distributed in forest or savanic vegetations of the Americas. The anatomy of their vegetative organs is diversified and useful on taxonomic grounds. We aimed to describe the morphoanatomy of the vegetative system of Encyclia chapadensis L. C. Menezes, E. linearifolioides (Kraenzl.) Hoehne, and E. osmantha (Barb. Rodr.) Schltr., emphasizing these characters that are both, helpful to set them apart and reflect the ecological conditions of their habitats. Some observed characters reflect adaptations to water restriction (hypostomatic leaves with hypodermis, roots with thick velamen, differentiated in endo and epivelamen, pseudobulbs with water- storage cells and thick cuticle) and mechanical reinforcement for support tissues (vascular bundles with fibers, presence of extravascular fibers and thickening in “fi” in the radicular cortex), indicating that some anatomical features reflect some abiotic conditions of the environment. The studied taxa can be differentiated through leaf, stem and root characters.