Gochnatia polymorpha: macro-and microscopic identification of leaf and stem for pharmacognostic quality control

ABSTRACT

Gochnatia polymorpha (Less.) Cabrera, Asteraceae, is popularly known as cambará and cambara-de-folha-grande in Brazil. It is used in traditional medicine to treat respiratory and gastrointestinal disorders. Pharmacological studies revealed anti-inflammatory, antispasmodic, antibacterial and antiviral activities. The goal of this paper was to carry out morphological and anatomical studies in order to describe the aerial parts of G. polymorpha. The botanical material was collected, fixed, and prepared according to usual light and scanning electron microtechniques. The leaves are simple, oblong-lanceolate to elliptical-lanceolate in form with mucronate acute apex, rounded base, entire or slightly toothed margin, and short petiole. In transection, the epidermis is uniseriate along the leaf blade. A subepidermal layer next to the adaxial side is present. Anomocytic stomata are seen only on the abaxial surface. Capitate glandular trichomes and T-shaped non-glandular trichomes occur on the leaves. The mesophyll is dorsiventral and minor collateral vascular bundles are enclosed by a sheath of thick walled parenchymatic cells. The midrib is biconvex and the petiole has a circular shape. The epidermis of the stem consists of a single layer of cells with glandular and nonglandular trichomes. The vascular cylinder shows typical structure and perivascular fiber caps are next to the phloem.