|Listed||July 13, 1989|
|Description||Perennial with linear leaves and clusters of blue and violet flowers.|
Penland beardtongue, Penstemon penlandii, is a short herbaceous perennial with showy flowers, linear leaves, and clumped stems up to 10 in (25 cm) tall. The flower clusters (inflorescences) consist of 5-15 flowers with blue lobes and a violet throat. The fruits are small brown capsules.
The species is restricted to shale barren badlands at Middle Park, a sagebrush basin in north-central Colorado. The barrens consist of Upper Cretaceous Niobrara and Pierre Shale and of Tertiary siltstone sediments at an elevation of roughly 7,700 ft (2,350 m). Osterhout milk-vetch (Astragalus osterhoutii ), which shares the same habitat, was federally listed as endangered along with Penland beardtongue.
Penland beardtongue was discovered at Middle Park in 1986. Because of its recent discovery and the fact that it is unknown in other areas, its historic range remains speculative. Populations of its nearest relatives (P. paysoniorum and P. gibbensii ) lie about 150 mi (240 km) to the northwest. Botanists speculate that this species may be derived from a more northern species. Penland beardtongue is important to biogeographic studies since it may hold clues to past floristic migrations. The 1986 discovery of the species involved a population of about 5,000 plants occurring over a series of shale badlands between Troublesome Creek and Sulphur Gulch, north and east of Kremmling, Colorado (Grand County). The habitat area is approximately 1.5 mi (2.4 km) long and 0.5 mi (0.8 km) wide. In the summer of 1988 an additional small population of about 500 plants was discovered to the north. Penland beardtongue has been found nowhere else. The 1992 recovery plan for the Penland beardtongue and Osterhout milk-vetch noted that the species is known primarily from the larger 5,000 individual population.
The major threat to Penland beardtongue is posed by recreational off-road vehicles, which disrupt the fragile shale barren habitat. Numerous dirt roads cross the Troublesome Creek locality, providing access to off-road vehicles. In addition, mining has occurred in the area in the past and any resumption would pose an additional threat to the habitat.
The species is likely a remnant of a previous extension of the Wyoming flora southward during glacial periods. As such, it is naturally restricted to the small area of suitable habitat still available in Middle Park. Expansion and migration to possibly suitable habitats elsewhere is blocked by the high mountains surrounding Middle Park.
Conservation and Recovery
Beardtongue populations are found on both private land and federal land managed by the U. S. Bureau of Land Management (BLM). As a first step in conserving the species the U. S. Fish and Wildlife Service has recommended that the BLM monitor the effects of off-road vehicles on plant populations. The 1992 recovery plan—which addresses recovery efforts needed for both the Penland beardtongue and Osterhout milk-vetch—outlines the primary recovery objective, the conservation of existing populations for the foreseeable future. Removal of the species from the list of endangered and threatened species (delisting) is considered unlikely because of the species' small natural populations, limited habitat, and the persistent nature of potential threats. Despite the unlikelihood of delisting, the recovery plan describes a number of efforts recommended to conserve existing populations, including the establishment of land management designations and development and implementation of habitat management programs for known populations of both species on private and public lands. The inventory of any remaining unsurveyed suitable habitat will also aid in conservation, as will research into the species' life history and ecology and the monitoring of existing populations. The adjustment of management practices will be undertaken as necessary and indicated by a downward trend of populations or evidence of physical habitat degradation.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
P.O. Box 25486
Denver Federal Center
Denver, Colorado 80225
U. S. Fish and Wildlife Service. 1992. "Osterhout Milkvetch and Penland Beardtongue Recovery Plan." U. S. Fish and Wildlife Service, Grand Junction, Colo.
Weber, W. 1986. "Penstemon penlandii, Scrophulariaceae from Colorado." Phytologia 60: 459-461.