Secretory structures in Cochlospermum regium (Schrank) Pilg. (Bixaceae): Distribution and histochemistry

Cochlospermum regium (Schrank) Pilg., known as the yellow cotton tree, is a small shrub with a number of pharmacological properties. A series of chemical compounds produced by the plant may be associated with secretory cells and tissues, such as idioblasts, trichomes and ducts. Thus, the aim of this study was to identify the secretory structures and major classes of compounds in vegetative organs of C. regium. Leaf, stem and root samples were collected, and transverse and longitudinal sections were examined by routine anatomical and histochemical methods. The results revealed that the leaves, roots and stems of C. regium are rich in ducts and idioblasts with a variety of secondary metabolites, justifying its wide use in phytotherapy.   Key words: Yellow cotton tree, ducts, idioblasts.