Cirsium tukuhnikivatzicum, A New Species of Thistle Endemic to the La Sal Mountains of Utah

Abstract

Abstract— Cirsium (thistles) have long been considered one of the most taxonomically challenging groups of plants in western North America. However, the relationships among thistles have become clearer thanks to recent molecular phylogenetic work. The results of this work revealed that Cirsium eatonii var. eriocephalum was polyphyletic, consisting of three distinct evolutionary lineages. Each of these lineages was also found to be distinct morphologically as well as geographically. Multiple lines of evidence thus indicated that Cirsium eatonii var. eriocephalum consisted of at least three distinct species. The first species recognized was the previously named C. scopulorum. The second lineage was recently named and described as Cirsium funkiae. The third lineage is here described as a new species, Cirsium tukuhnikivatzicum. Mount Tukuhnikivatz is a prominent backdrop against this new species of thistle. Tukuhnikivatz is also the Southern Paiute word for “place where the sun shines longest” and Ute word for “where the sun sets last.” The specific epithet tukuhnikivatzicum is therefore used to indicate the distribution of this species, while also acknowledging and paying tribute to the Southern Paiute and Ute legacy of use of the La Sal Mountains. There was a taxonomic lag time of 112 yr between the first specimen collection and the new species description presented here.