Adventitious roots morphoanatomy of Rheophytes <I>Dyckia brevifolia</I> (Baker) and <I>D. distachya</I> (Hassle) (Bromeliaceae)

Abstract

Rheophytes are species of plants that occur in the nature exclusiveiy beside swift-running streams and rivers which experience frequent and sudden floods. This study relate the morphoanatomical characteristics of the Dyckia brevifolia Baker and D. distachya Hassler two species of rheophytes bromeliad that occur at south Brazil. The roots of the two species are similar anatomicaly and they are constituted by ring tissue, cortex and central cylinder. The one-Iayer epidermis with root-hairs further covering. The cortex is constituted by outer parenchyma, sclerenchymatic ring, inner parenchyma and endodermis. The number of.exodermis layers is distinct among these species, it is higher in D. distachya. At the general way, the features find out in the adventiceus roots of D. brevifolia and D. distachya are similar at the others Bromeliaceae species. However, such characteristics must to favor the establishment and survival of these species in the rheophytic environment.