[Ranunculus acriformis var. aestivalis L.D. Benson]
Stems hirsute. Flowers: receptacle obpyriform to cylindric; sepals reflexed ca. 2 mm above base, pubescence of spreading hairs; petals 8-11 mm. Achenes: beak 0.4-1 mm. Flowering summer (Jul-Sep). Meadows; 2100-2900 m; of conservation concern; Utah. Ranunculus acriformis var. aestivalis is known from two sites in southern Utah, a saline meadow south of Panguitch in the Sevier River Valley and a riparian meadow in Boulger Canyon, Emery County. R. Van Buren et al. (1994) treated this variety as a distinct species, R . aestivalis , emphasizing the saline habitat of the Sevier Valley population. The morphologic differences between R . acriformis var. aestivalis and the other varieties of R . acriformis are minor, and the habitat of the single Emery County specimen is typical of the species. I prefer to retain this taxon in R . acriformis . The DNA data of Van Buren et al., based on a total of eight populations of the three varieties, are consistent with either interpretation, because the three varieties form a single clade with R . acriformis var. aestivalis as sister group to the other two.
This project made possible by National Science Foundation Award 1410069