Comparative Morphology and Surface Microsculpture of Cypsela in Some Taxa of the Asteraceae and Their Taxonomic Significance

MACRO- and micromorphological characteristics of cypsela in 13species and one subspecies representing genera: Carthamus L.,Centaurea L. Cichorium L., Cirsium Mill., Crepis L., Lactuca L.,Picris L., Reichardia Roth, and Sonchus L.; belonging to the two tribesCardueae and Cichorieae of the Asteraceae were examined understereomicroscopy and scanning electron microscopy (SEM). Thecypsela macromorphological features including; cypsela lengthmeasurements, colour, shape, surface texture and the number of ribswhen present as well as the abscission scar characteristics and detailsof the surface, microsculpture peculiarities were investigated. Thecypsela length and colour presented a minor taxonomic value.However, the other remaining features were proved to be primarilydiagnostic at the species level and sometimes at the genus level but notdistinctive for any of the two tribes. In addition, these features werevery useful in the precise technical identification of the examinedcypselae. An identification key for the studied taxa, based on theinvestigated aspects, was presented.