MORFOANATOMIA DA RAIZ, CAULE E FOLHA DE PISTIA STRATIOTES L.

Pistia stratiotes L. e uma macrofita aquatica monocotiledonea, considerada planta daninha pertencente a familia Araceae. Essa especie possui importantes aplicacoes na medicina, fitorremediacao de ambientes naturais e para fins emolientes. No entanto, a morfoanatomia das estruturas vegetativas desta planta ainda e pouco conhecida. O objetivo do trabalho foi analisar os aspectos morfoanatomicos dos orgaos vegetativos de Pistia stratiotes L., contribuindo assim, para a melhor identificacao e utilizacao da especie no aspecto ecologico. As amostras botânicas foram coletadas na Universidade Estadual de Maringa (UEM), confeccionadas lâminas semipermanentes de cortes transversais de caule, raiz e cortes paradermicos das duas superficies da folha; em seguida, todas as estruturas foram coradas com safrablau. As raizes desta planta sao fasciculadas, o caule do tipo estolao, as folhas apresentam filotaxia rosulada e venacao actinodroma. Pistia stratiotes tem caracteristica hidromorfica, e anfiestomatica, com muitos cristais, parenquima homogeneo e esponjoso na folha, muito aerenquima por toda a sua extensao e com grande quantidade de tricomas tectores e glandulares. Em sintese, nosso manuscrito demonstrou como estudos anatomicos atraves de ilustracoes cientificas sao importantes para entender as relacoes desta ou de outras plantas aquaticas com o meio ambiente. Assim, desenvolver outros estudos anatomicos com esta ou outras especies poderia ajudar na compreensao dos mecanismos utilizados por eles no ambientes aquaticos. MORPHOANATOMY OF THE ROOT, STEM AND LEAF OF PISTIA STRATIOTES L. Pistia stratiotes L. is an aquatic macrophyte monocot, considered as a weed belonging to the Araceae family. This species has important applications in medicine, phytoremediation of natural environments and for emollient purposes. However, the morphoanatomy of the vegetative structures of this plant is still little known. The main objective of this study was to analyze the morphoanatomic aspects of the vegetative organs of P. stratiotes contributing to the better identification and use of the species in the ecological aspect. The botanical specimens were collected at the State University of Maringa (UEM), and semi-permanent slides were made of the cross section of stem, root and surface of leaf and were stained with safrablau. The roots of this plant are fasciculate, the stolon-like stem, the leaves show rosette phylotaxis type and actinodroma venation. P. stratiotes have hydromorphic characteristics, it is amphistomatic, with many crystals, homogeneous and spongy parenchyma in the leaf, very aerenquimous throughout its length and with great quantity of tectorial and glandular trichomes. In summary, our manuscript demonstrated as anatomical studies through scienctific illustrations are important to understand the relationships of this or other aquatic plants with environment. Thus, to develop other anatomical studies with this or other species would can help in understanding the mechanisms used by them in the environments aquatic.