Anatomy and histochemistry of Tarenaya hassleriana (Cleomaceae), an interesting medicinal species

Abstract

Plant decoction of Tarenaya hassleriana is used as a traditional medicine in the Río de La Plata area. It has rubefacient, digestive, and antiscorbutic properties. The aim of this study was to investigate leaf and stem microcharacters to identify this species from whole or fragmented samples. The usual techniques of optical microscopy were employed. Histochemical tests for starch, lipophilic substances, phenolic substances, and mirosina were used. The main differential traits were: leaflets with eucamptodromous venation, amphistomatic with anomocytic stomata type; uniseriate and pluriseriate glandular trichomes, with unicellular and pluricellular heads containing lipophilic substances; dorsiventral mesophyll; stem with a primary cortex formed by tangential collenchyma followed by parenchyma; the secondary vascular cylinder surrounding the pith with starch, polyhedral microcrystals and spherocrystals. Idioblast of myrosin were detected in the epidermis and parenchyma of leaves and stems. The micrographic parameters described ensure a correct identification of T. hassleriana.