North Park Phacelia

Phacelia formosula

Description

North Park phacelia is considered either a biennial or a short-lived perennial. A first-year plant produces a basal rosette of large, elongated leaves. The plant matures in its second year when its branched stems reach a height of about 9 in (23 cm). The curled leaves are oblong and pinnately cleft into many narrow lobes. A long stem produces a coiled spray of violet flowers. After setting seed, the plant dies. Many first-year plants do not survive to reproduce.

Habitat

North Park phacelia grows in thin soils derived from sandstone. It is found on the bluffs overlooking the Michigan and North Platte Rivers in the uplands of extreme north-central Colorado. Many plants cling to steep-sided ravines, where erosion can be severe. Because the vegetative cover is low, incident light is high throughout the growing season. Temperatures are very cold in winter and moderate in summer. Precipitation comes as snow and in summer storms. Because the species is a biennial or a short-lived perennial, the precipitation in any given year can have a profound effect on the number of individuals that germinate and survive.

Distribution

This plant is endemic to the North Park region of north-central Colorado, an area of about 384,000 acres (155,400 hectares). Only two populations of North Park phacelia are known from riverbank bluffs, situated 5 mi (8 km) apart in Jackson County. Of these two, the smaller population increased from a low of 22 plants in 1979 to around 200 in the favorable growing season of 1981. The second population was discovered in 1981 and consists of five discrete sites scattered along an 8-mi (13-km) stretch of the North Platte River. One of these sites supports the largest known concentration of about 2,500 plants, while the others sustain less than 20 plants each.

Threats

The North Park phacelia is threatened by off-road vehicle activity and cattle trampling. The species' slow reproduction intensifies these threats. One population, situated between an airport and a campground, has suffered considerable damage. The larger North Platte population is on land known to have recoverable mineral resources. Most of the area is managed by the U. S. Bureau of Land Management (BLM) and has been leased for coal, oil, and natural gas exploration. Grazing and trampling livestock also pose a threat to this population.

Conservation and Recovery

The U. S. Fish and Wildlife Service (FWS) has the responsibility of consulting with the BLM to ensure that mineral and grazing leases do not damage North Park phacelia populations. A 340-acre (138-hectare) tract of phacelia habitat on public land has been designated as a natural area by both the BLM and the state of Colorado. The goal of the FWS recovery plan is to establish at least five secure sites of 500 or more mature plants. Although this would justify revising the status of the plant to threatened, the species would not be considered fully recovered until the number of secure populations exceeded ten.

Contact

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

References

Atwood, N. D. 1975. "A Revision of the Phacelia crenulatae Group (Hydrophyllaceae) for North America." Great Basin Naturalist 35 (2): 161-162.

U. S. Fish and Wildlife Service. 1986. "North Park Phacelia Recovery Plan." U. S. Fish and Wildlife Service, Denver.

Wiley, K. L. 1979. "Status Report on Phacelia formosula Osterhout." Report. U. S. Fish and Wildlife Service, Denver.