Trichome micromorphology and its significance in the systematics of Convolvulus L. (Convolvulaceae)

Trichomes of 35 species of the genus Convolovulus and one species of the genus Calystegia (C. sepium) were investigated using light and scanning electron microscopy. The trichomes show a great variation, which provides valuable data for sections and species delimitation in Convolvulus. Trichomes of Convolvulus are nonglandular, simple, and basifixed or rarely asymmetrically medifixed. Characters of taxonomic interest were the degree of curviness (straight to spiral), orientation relative to the epidermal surface (appressed to erect), and presence of papillae on trichome surface. The trichomes are divided into two basic types: cylindrical and flattened ribbon-like.