Taxonomical significance of the morphological and scanning electron microscopic surface patterns of cypselas in some members of the tribe Heliantheae (Asteraceae)

Data on morphological, histological and scanning electron microscopic studies on cypselas in 23 species belonging to nine subtribes of the tribe Heliantheae (Asteraceae) are presented. Developmental anatomy in two representative species showed that the two zoned ovary wall matures into a pericarp where the two zones are cemented by a black coloured deposition. The middle layers degenerate at maturity and only two layered seed coat persists. The surface patterns as revealed by SEM are species specific with some common similarities. Based on these characters supplemented by the histo‐morphological characters of the cypselas, a tentative key for identification and interrelationships of the species studied have been prepared. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)