Hyobanche (Scrophulariaceae) is a genus of holoparasites consisting of five to eight species endemic to Southern Africa. Hyobanche sanguinea L. was the first species described in 1771. The remaining species were described individually from 1901 - 1923. No systematics studies have yet been conducted on the genus as a whole and it is unclear as to how many species there are from a review of herbarium specimens and the taxonomic literature. To initiate a systematics study of the genus, we sampled 11 populations of H. sanguinea, H. glabrata Hiern, H. rubra N. E. Br. and H. atropurpurea H. Bol. for ISSR analysis. All but one (H. atropurpurea) of the sampled species has red to pink, tubular flowers that fit into the paradigm of a bird-pollination syndrome. However, visitors to these showy flowers have not been reported. The floral pubescence of H. glabrata is intermediate between H. sanguinea and H. rubra, but its overall morphology is most similar to the latter. Banding patterns from seven primers reveal that H. glabrata has the most within-population diversity, whereas individual accessions of H. sanguinea are the most homogeneous. All taxa sampled had species-specific and population-specific banding patterns, suggesting that these four species are valid. In addition, H. rubra and H. glabrata have the most shared bands and these two species share more bands with H. sanguinea than with H. atropurpurea.

Key words: genetic diversity, holoparasite, Hyobanche, ISSR, parasitic plants, Scrophulariaceae