Caracterização morfológica e anatômica do caule subterrâneo de Cyperus articulatus L. e C. prolixus H. B. K. (Cyperaceae) em desenvolvimento vegetativo.

Abstract

The aromatic species Cyperus articulatus L. and C. prolixas H.B.K., by whom underground stems is extract an essence used at cheiro-do-Pará perfume, are popularly known as priprioca and pripriocão respectively. For these species, there are no studies about underground stems development. The purpose this study was to characterize the morphology and anatomy of underground stems at different vegetative development stages, as well as to identify the secretory structures. The botanical vouchers were collected from test area of the Federal Rural University of Amazônia (Belém city) and fixed in FAA 50. Histological sections, histochemical testes, parafin inclusion, maceration and coloration to astra blue and basic fucsin were used. The complex stems is composed of rhizome and corm overlaing to cataphylls and produced from vegetative shoot apex. The corms are spherical to elliptical, and rhizomes are cylindrical. Adventitious roots and aerial scape are origined from corms. These two stems are alternated with plagiotropic growth. As regard to anatomy, in cross sections, protoderm, procambium, fundamental meristem and primary thickening meristem (PTM) are differentiated from the apical meristem of the shoot apex. Phenolic idioblast and other with oil occur among the ground meristematics cells. PTM produced amphivasal vascular bundles and parenchyma to inner and to outer, origining cortical and medullar regions. After, endodermis and pericycle are differentiated. In rhizomes cross sections, sclerenchyma bundle are formed in the outer cortex and at C. articulatus around the endodermis. Schizo-lysigenous aerenchyma occurs in the inner cortex of C. articulatus rhizome. In C. prolixas, starch parenchyma are observed in the inner cortex. Afterward PTM becomes a pericycle later meristem. In corms cross sections, PTM produced adventitious roots too. The PTM stopped when the endodermis and derivated cells of inner cortex were differentiated. However, the pericycle continues active producing roots and secondary vascular system (SVS), for this it's called of secondary thickening meristem (STM), what characterize a thicken growth later for the corm. Concluded that corms are reserve and propagation organs and rhizomes to expansion, while PTM and STM are very important to development of the underground stems. In addition, secretory idioblasts containing oil are connected to smell present on two stems.