The following Participating Institutions are custodians for this species in the CPC National Collection:
The Arboretum at Flagstaff
The conservation of Asclepias welshii is fully sponsored.
Joyce Maschinski, Ph.D. contributed to this Plant Profile.
Welsh's milkweed is an herbaceous perennial with extremely hairy and broad ovate leaves. Cream-colored flowers with rose-tinged centers are produced in a ball shaped cluster from May to June. Large seeds with rudimentary tufts of hairs develop and are dispersed from July to early September. However, two other growth forms are known to exist. What is designated as the primary growth form has narrow linear leaves and looks very similar to A. subverticillata. A second form exhibits intermediate leaf traits of the primary form and the first description (referred to as the mature form) and is called the secondary form. (Palmer & Armstrong 2000) This species grows in coral pink colored sand dunes and was listed as threatened in 1987 in response to increased threats of off-road vehicle (ORV) activity (USFWS 1987).
Distribution & Occurrence
A. welshii grows on active sand dunes in sagebrush, juniper, and ponderosa pine communities, between 4700 and 6250 ft in elevation. (NatureServe 2001)
Co-occurring species include Wyethia scabra, Calamovilfa gigantea, Chrysothamnus nauseosus and Sophora stenophylla.
|At the time of listing, there were thought to be no more than 11,000 individuals of this species, with populations scattered in a fairly localized area in Utah and on the Utah-Arizona state line. (USFWS 1987)
There are now three Utah populations: Coral Pink Sand Dunes (ca. 10,000 individuals), 2) Sand Hills ( ca. 500 individuals), 3) Sand Cove (ca. 600 individuals). At least two others are known to exist near Page County, Arizona and in the Paria-Vermillion Cliffs Wilderness are near the Utah/Arizona border in Kane County, Utah and Coconino County, Arizona (Palmer & Armstrong 2000).
Conservation, Ecology & Research
Reproduces mainly by rhizomes, but by seed when conditions are right (Palmer & Armstrong 2000).
While a number of species in the Asclepias genus contain toxins that make them poisonous to grazers (including cattle), this species has been shown to be palatable and non-toxic to range livestock. However, cattle seldom traverse the sand dunes where this species occurs, so grazing is likely not a major threat to this species. (USFWS 1987)
Palmer, B.C.; Armstrong, L. Demography and Monitoring of Welsh's Milkweed at Coral Pink Sand Dunes. Southwestern rare and endangered plants: proceedings of the third conference; September 25-28; Flagstaff, AZ. In: Maschinski, Joyce; Holter, Louella, edito