MACRO AND MICROSCOPIC CHARACTERS OF THE BAY LEAF

Abstract

Commonly named bay or bay laurel, Laurus nobilis L. is a tree with smooth caulinar surface, many branches and leaves, yellow inflorescences and dark spherical fruits. The leaves are scented and used as spice in culinary and as digestive, carminative and antispasmodic in folk medicine. Phytochemical essays have identified various components of the essential oil, mucilage, sesquiterpene lactones, tannins and alkaloids. Owing to its relevance in culinary and phytotherapy, and the lack of morpho-anatomical information for quality control analysis, this work has dealt with leaf macro and microscopic characters of this species. Adult leaves were fixed, freehand sectioned and either stained or prepared according to usual microchemical tests. The leaves are alternate, simple, entire and obovate-lanceolate. The epidermal cells are sinuous and coated with a moderately thick cuticle. Paracytic stomata occur on the abaxial side and some unicellular non-glandular trichomes are seen. The mesophyll is dorsiventral and minor vascular bundles with sclerenchymatic sheath extension are embedded in the chlorenchyma. The midrib has biconvex cross-section and the petiole is plain-convex. Both are traversed by a collateral vascular bundle, enclosed in an incomplete sclerenchymatic sheath. Secretory cells, spherical and relatively large, are found in the leaf.