Systematics/Phytogeography / Taxonomie/ Section
Shultz, Leila M. .
Systematic relationships of sagebrush species in western North America (Artemisia subgenus Tridentatae: Asteraceae/ Anthemideae).
Within Artemisia, sens. lat.,Â subgenus Tridentatae sect. Tridentatae forms a monophyletic lineage of relatively recent origin. Unresolved, however, is the relationship involving several woody species that would extend the geographic distribution of sagebrush into the California chaparral and the Great Plains of North America: A. bigelovii (Bigelow sage), A. filifolia (Sand sage), A. californica (California sagebrush), and A. nesiotica (Island sage). These four species differ primarily from sect. Tridentatae in having heterogamous (rather than homogamous) flowering heads. Two independent reports on the molecular phylogeny of Artemisia within the Artemisiinae lineage (Watson et al. 2002; Riggins 2008) suggest a relationship of these four species with members of subg. Tridentatae. Based on these reports as well as my morphological and anatomical studies, I am treating the species with a putative relationship as a separate, new, section within the subgenus. Subg. Tridentatae is clearly distinct from shrubby species of the Old World (treated as Artemisia subg. Seriphidium).
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Artemisia/Flora of North America
1 - Utah State University, Department of Wildlife Resources, Floristics Lab, Old Main Hill 5230, Logan, UT, 84322-5230, USA
Presentation Type: Oral Paper:Papers for Sections
Date: Wednesday, July 30th, 2008
Time: 4:00 PM