|Listed||August 21, 1985|
|Description||Perennial herb with spatula-shaped leaves and lavender flowers.|
|Habitat||Shaded crevices on damp ledges of limestone cliffs.|
|Threats||Collectors, rock climbers.|
Maguire primrose (Primula maguirei ) is a low-growing perennial herb with one or several slender scapes (leafless stems) up to 4 in (10 cm) tall. Each scape bears one to three conspicuous, five-petaled lavender flowers in the spring. Spatula-shaped leaves, rounded at the tip and about 2 in (5 cm) long, are grouped at the base of the plant.
Maguire primrose grows on damp ledges and in shaded crevices along canyon walls. It is found mainly on north-facing, moss-covered cliffs of 4,800-5,500 ft (1,463-1,676 m) in elevation. Geological formations are composed of carboniferous limestones and dolomites. Coniferous shrubs and trees (aspen, spruce, and fir) are conspicuous features of the plant community.
This species has been found only in extreme northern Utah in Logan Canyon (Cache County) near the town of Logan.
When Maguire primrose was listed as threatened in 1985, there were nine known populations, all in Logan Canyon. The largest population contained 100 plants, other populations fewer than 30 plants each. In 1990 the population was estimated at 3,000 in six sites covering an area of 0.5 mi by 10 mi (0.8 km by 16.1 km). Plant sites are managed by the Forest Service as part of the Wasatch National Forest or by the State of Utah.
Maguire primrose is a beautiful flowering plant, often casually collected by hikers. Because of its low numbers, collecting at any level poses a threat to the species. Rock climbers, too, have destroyed plants; to secure handholds, climbers often "clean" vegetation, including the primrose, from cracks and ledges as they climb. Where sites have been undisturbed by climbers, seedlings are being reestablished, and reproduction appears unimpeded.
The largest and most vigorous primrose populations are threatened by a proposed highway construction project that would remove canyon-bottom tree groves and alter the lower cliffs in Logan Canyon. In addition to raising temperatures and lowering humidity in the canyon, an expanded highway would allow hikers and climbers easier access to plant sites.
Conservation and Recovery
The Forest Service and the State of Utah are examining alternatives to the proposed construction that would balance the need for an improved canyon road with a measure of protection for the primrose.
The Maguire primrose has been cultivated under controlled greenhouse conditions with some success. A vigorous nursery population would provide a buffer against a sudden decline in the wild population and provide stock for transplantation to new locations. Currently, population trends are being monitored annually, and research into the plant's biology is continuing.
U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
P.O. Box 25486
Denver Federal Center
Denver, Colorado 80225
Beedlow, P. A., and others. 1980. " Primula maguirei L. Wms. (Primulaceae): A Preliminary Report on the Population Biology of an Endemic Plant." Plant Bio-Resources, Logan, Utah.
U. S. Fish and Wildlife Service. 1985. "Final Rule to Determine Primula maguirei (Maguire Primrose) to Be a Threatened Species." Federal Register 50 (162): 33731-33734.
Welsh, S. L. 1979. "Status Report: Primula maguirei. "U. S. Fish and Wildlife Service, Denver.
Welsh, S. L., and K. H. Throne. 1979. "Illustrated Manual of Proposed Endangered and Threatened Plants of Utah." U. S. Fish and Wildlife Service, Denver.