Biosystematic Investigations in South Florida Populations of Ruellia (Acanthaceae)

Relationships of the putative Ruellia species, R. caroliniensis, R. ciliosa, R. heteromorpha, and R. succulenta were analyzed by population sampling, investigation of chromosome numbers, garden transplants, and hybridization experiments. Character data from 25 local, Florida populations and from transplants were evaluated. Some interfertility of these “taxa” was demonstrated, as was some interfertility with other species occurring in the eastern United States. Chromosome numbers are n = 17 and 2n = 34. The effect of different breeding systems on population structure is discussed. Total evidence suggests that the 4 “taxa” in question be considered ecological races of a single species widespread in the eastern United States, namely R. caroliniensis.