Taxonomy of Cordylanthus subgenus Hemistegia (Scrophulariaceae)

A taxonomic revision ofCordylanthus subg.Hemistegia based on evidence from morphology, chromosome numbers, habitat, ecology, and geographic distribution is presented, recognizing four species and five subspecies. Three new combinations on the subspecific level are proposed. The first chromosome counts for subg.Hemistegia are reported with haploid numbers ofn = 14, 15, and 21. Each species is illustrated with line drawings showing habit and floral morphology; distribution maps indicate sites of known populations. The possible extinction ofC. mollis ssp.mollis andC. pamatus is discussed, and the urgent need for preservation of their saline and alkaline habitats is emphasized.