Contributions to the Taxonomy of Chrysothamnus viscidiflorus (Astereae compositae) and Other Chrysothamnus Species Using Paper Chromatography

Abstract

Chromatographic patterns of phenolic compounds were determined for each of the common subspecies of the widespread range shrub Chrysothamnus viscidiflorus (low rabbitbrush), some other Chrysothamnus taxa, and some related Compositae genera. Each subspecies of C. viscidiflorus exhibited variation across its geographical range, but within sites the patterns were consistent. Chromatographic pattern distributions suggest a predominance of self-pollination in C. viscidiflorus; however, the limited outcrossing has important genetic implications. Analysis of the chromatographic spot patterns revealed three groups or clusters within C. viscidiflorus. Surprisingly, C. greenei clustered more closely to some C. viscidiflorus subspecies than these subspecies clustered with other C. viscidiflorus subspecies. C. greenei clustered with ssp. lanceolatus and stenophyllus. Ssp. viscidiflorus clustered s > 0.70 with ssp. latifolius and a group of collections intermediate in morphology between viscidiflorus and lanceolatus. It shares some intense spots with these taxa. Subspecies puberulus did not cluster at s = > 70 with any other taxon. Chromatographic data supported the independent species status of C. linifolius and the internal integrity of the three large species complexes in Chrysothamnus-C. viscidiflorus, C. nauseosus, and C. parryi. The genus Petradoria had high a values with Chrysothamnus, as did Haplopappus bloomeri. Other shrubby Compositae (Xanthocephalum sarothrae and Lepidospartum latisquamum) had much lower s values with Chrysothamnus. Chromatography complements morphology in delimiting taxonomic rank. Each Chrysothamnus taxon should be evaluated on its merits.