Abstract

Platostoma africanum P. Beauv. is a tropical plant species valued for its efficacy in traditional medicinal system in West Africa. Although studied for its chemical properties, no cytogenetic study has been reported on this plant species. Axillary buds obtained from the growing plants were used to conduct mitotic study. Results obtained in this study showed that P. africanum is a diploid species with chromosome number, 2n = 10. The mean chromosome length was 3.93 µm and chromosomes ranged from 3.08 to 5.39 µm, with a haploid set length of 19.64 µm. The karyotype showed assymetry with a formula, 1m+1sm+2a+1t and indicated good adaptation and advancement in evolution in this species. This is the first report of the chromosome number in this indigenous medicinal plant species.

Key words: Cytology, mitosis, medicinal plants, Lamiaceae.