Ruth’s chicken sage is a perennial herb in the sunflower family that is endemic to the Navajo Sandstone canyons in and near Zion National Park in southwestern Utah. It was first collected in 1935 but not recognized as a distinct taxon until the 1970s. This species usually grows in cracks and ledges high up on slickrock cliffs, well out of eyesight (and reach) of botanists and hikers. One population, however, grows in the lime-rich joints of the low stone wall lining the switchbacks in Refrigerator Canyon (the route to the popular Angel’s Landing viewpoint, traversed by millions of tourists over the years). These walls were built by workers with the Civilian Conservation Corps in the 1930s, suggesting that the plant arrived after construction was completed.
Ruth Ashton Nelson collected this species in the “Walter’s Wiggles” section of the canyon (named for an early park superintendent, and not for my dance moves) and brought it to the attention of Arthur Holmgren, Leila Shultz, and Tim Lowrey of the Intermountain Herbarium at Utah State University. At the time, Ruth was completing her illustrated flora of Zion National Park, published in 1976 (long out of print, but well worth looking for on eBay). The Utah State team realized this was a new species allied with other herbaceous species of Artemisia (sagebrush) and not Tanacetum (tansy), a more distant relative. They published it as a new species after Ruth in the resurrected genus Sphaeromeria, which contained several other herbaceous sage-like plants with rayless yellow flower heads and silvery, lobed leaves from the western US. More recent molecular studies have found that Sphaeromeria nests within the sagebrushes and the species has been renamed Artemisia ruthiae.
Ruth Nelson spent many years documenting the flora of Zion and other national parks. She wrote the first flora of Rocky Mountain National Park for her master’s thesis at Colorado Agricultural College (now Colorado State University). Ruth visited the Rocky Mountain Herbarium at the University of Wyoming (the largest in the region) to verify the identification of some of her specimens, where she met the curator, Aven Nelson. Impressed with her abilities, Nelson hired Miss Ashton to be the assistant curator of the herbarium. Aven was a widower in his early 70s with two grown daughters about the same age as Ruth (then 35 years old), but the two hit it off. They married in 1931 and remained a couple until Aven’s death in 1952. The Nelsons botanized across the west, naming many new species from their trips to the desert southwest and Alaska. – Walter Fertig, 8 June 2025
