2017 Volume 68 Issue 3 Pages 193-198
Commelina, the pantropical and largest genus in Commelinaceae, consists of ca. 205 species with characteristic conduplicate involucral bracts. Previous phylogenetic studies of Commelina, which mainly used African and North American species, suggested that the ancestral character state of the margins of the involucral bracts of Commelina was free and that free to fused occurred only once. To test this evolutionary scenario, we performed parsimony and likelihood analyses with partial matK sequences using 25 individuals from 11 species of Commelina, primarily from eastern and southeastern Asia, with Aneilema and Pollia as outgroups. Results showed that Commelina comprises two major clades, one consisting of four species, and the other consisting of seven species. Species with free margins of the involucral bracts were in both major clades: C. suffruticosa in the first clade and C. coelestis, C. communis, C. diffusa, C. purpurea and C. sikkimensis in the latter. The phylogenetic trees suggested that the number of shifts is fewer when the ancestral state was fused and that there were two parallel evolutionary trends toward free.
