Cytomorphological Studies on the Echinops L. in the Nigerian Asteraceae (Compositae)

Abstract

Members of the genus Echinops are now widely used in treating brain disorders, ophthalmic problems, chronic fever, pains in the joints and inflammations. They are aphrodisiac and are used for treating pregnant women. The Nigeria species have not been discovered in this way. The plants are therefore being suggested to our scientists, chemists and agriculturists for possible screening for drug development. Cytomorphological studies on 4 taxa distributed in 3 species of the Echinops have been studied. Pollen fertility test of the species studied revealed that meiosis was normal with regular bivalent pairing. Thus the plants were normal and hybridization was not responsible for their differences. Chromosome counts for the 3 species are new reports (n=8 for E. giganteus var lelyi, E. gracilis and E. longifolius) and they are reported for the first time for the African Echinops. The base number 8 is suggested as the ancestral base number for the genus. The achene morphology of all the taxa studied are presented for the first time. Distribution maps of all the taxa studied are presented for the first time. The stomatal characteristics and achene morphology have been found to be a reliable taxonomic tool that would help to delimit the genus. The probable pathway of evolution has been traced for the genus for the first time.