Welsh's Milkweed

Asclepias welshii

Description

Welsh's milkweed,Asclepias welshii, is a perennial herb, 10-40 in (24-100 cm) tall, growing from a thickened rhizome. It bears large oval leaves and cream-colored flowers tinged with rose in the center. The flowers grow spherically in groups of 30 and are about 2.75 in (7 cm) in diameter. Welsh's milkweed reproduces both sexually and asexually, flowering May to June. Fruit and seed dispersal occurs from July to September.

Habitat

Welsh's milkweed grows on stabilized sand dunes associated with sagebrush, juniper, and ponderosa pine communities at 5,570-6,230 ft (1,700-1,900 m) elevation, or in sheltered pockets on the leeward slopes of actively drifting dunes. The plant grows in four situations: amongst other vegetation, on exposed shale, on fine grain exposed geological rock types, or in finer grained developed soils. It grows quickly enough to keep ahead of the moving sand dune as it drifts toward the location of the plant.

Distribution

The first plants were collected on the Coral Pink Sand Dunes in Kane County, Utah, in 1979. The plant is endemic to this region of south-central Utah.

Welsh's milkweed is found in only two places in Kane County: the Coral Pink Sand Dunes and 8 mi (13 km) to the northeast in the Sand Hills. In the Coral Pink Sand Dunes about 6,000 plants are scattered across a dune environment administered by the Bureau of Land Management. Perhaps 4,000 more plants grow on adjacent state lands that are part of the Coral Pink Sand Dunes State Park. An estimated 500 plants occur in the Sand Hills area.

Threats

Dunes plants are very sensitive to disturbance and may take years to recover from an environmental disruption. The major populations of Welsh's milkweed grow in the Coral Pink Sand Dunes, an area heavily used by off-road vehicles. These vehicles disturb or destroy plant life and destabilize the fragile dunes ecology. Some of the area has been leased for oil and gas exploration, but the exploration leases stipulate "no surface occupancy," which excludes drilling in the dune areas. Because most plants are growing on government land, management strategies will exclude off-road vehicles from the habitat areas and maintain restrictions on surface occupancy.

Conservation and Recovery

The state of Utah opposed listing Welsh's milk-weed because officials thought that a declaration of critical habitat would restrict off-road vehicle recreation, one of the reasons for which the Coral Pink Sand Dunes State Park was established and funded. A local off-road vehicle association, however, agreed to cooperate with the Fish and Wildlife Service (FWS) and has set up an educational program for its membership. The FWS does not anticipate listing to have a direct impact on state park activities.

Critical Habitat was designated to include 4,000 acres of sand dune habitat in the Coral Pink Sand Dunes and the Sand Hills area.

Contacts

U.S. Fish and Wildlife Service
Division of Endangered Species
P.O. Box 1306
Albuquerque, New Mexico 87103
http://southwest.fws.gov/

U.S. Fish and Wildlife Service
Division of Endangered Species
Denver Federal Center
P.O. Box 25486
Denver, Colorado 80225
http://www.r6.fws.gov/

References

Holmgren, N. H., and P. K. Holmgren. 1979. "ANew Species of Asclepias (Asclepiadaceae) from Utah." Brittonia 31(1):110-114.

Luckenback, R. A., and R. B. Bury. 1983. "Effects of Off-Road Vehicles on the Biota of the Algondones Dunes, Imperial County, California." Journal of Applied Ecology 20:265-286.

U.S. Fish and Wildlife Service. 1987. "Final Rule Determining Welsh's milkweed, Asclepias welshii to Be a Threatened Species with Critical Habitat." Federal Register52(208): 41435-41441.

U.S. Fish and Wildlife Service. 1991." Welsh's milk-weed, Asclepias welshii, Recovery Plan." USFWS, Denver. 29 pp.