Anatomia de raízes de nove espécies de Bromeliaceae (Poales) da regi？o amaz？nica do estado de Mato Grosso, Brasil

this study aimed to characterize the roots of bromeliaceae, aechmea bromeliifolia, a. castelnavii, a. mertensii (bromelioideae), dyckia duckei, d. paraensis, d. racemosa (pitcairnoideae), tillandsia adpressiflora, t. didistachae and t. paraensis (tillandsioideae), that occur in amazonian regions (mato grosso-mt), in order to find features of taxonomic value and ecological importance. the studied species are epiphytes and their roots are characterized by a multi-layered velamen, differentiated cortex, uniseriate endodermis and pericycle, polyarch vascular cylinder and medulla with thickened cell walls. anatomical structures, such as the number of layers and kind of cell wall thickening of the velamen, the kind of thickening of the exodermis and endodermis walls, the presence of idioblasts containing crystals and the number of protoxylem poles help seperate these species within different genera and subfamilies. the presence of mucilage canals in the cortex of a. castelnavii is a diagnostic feature. the roots of dyckia and tillandsia share more common features, so there is greater similarity between pitcairnioideae and tillandsioideae. roots with velamen, an exodermis with thickened cell walls constituting a mechanical layer, mucilage canals, air gaps in the inner cortex and idioblasts with crystals are structures adapted to the epiphytic habit.