Leaf and stem morpho-anatomy of Genipa americana L., Rubiaceae

"Leaf and stem morpho-anatomy of Genipa americana L., Rubiaceae." Genipa americana L., known as jenipapo, is a Rubiaceae species native to Brazil. Its leaves are used by the population as anti-diarrheic and febrifuge, and its stem as anti-hemorrhagic and for trauma injuries. Aiming to identify macro and microscopically mature leaves and young stems for the pharmacognostic quality control, this medicinal plant was investigated according to standard morpho-anatomical techniques. The leaves are simple, opposite, obovate-oblanceolate, presenting short petiole. The epidermis is uniseriate and coated with thin and slightly striate cuticle. The stomata are paracytic and restricted to the abaxial surface. It occurs non-glandular trichomes, uni and multicellular, predominantly on the abaxial surface. The mesophyll is dorsiventral. In cross-section, the midrib is plane-convex and the petiole is circular, both presenting one collateral vascular bundle in centric arrangement and minor ones. The stem shows phellogen installed superficially, annular collenchyma and a phloem cylinder outside the xylem one, both traversed by narrow parenchymatic rays. It is encountered idioblasts containing phenolic substances and calcium oxalate crystal-sand and druses.