|Listed||September 14, 1998|
|Description||Small, compact, rosette-forming annual herb.|
|Habitat||Small barren areas on decomposed granitic sands.|
|Threats||Urbanization; low numbers.|
Mariposa pussypaws (Calyptridium pulchellum ) is a small, compact, rosette-forming annual herb belonging to the purslane family. The smooth, slender, prostrate stems are 4-8 in (10.2-20.3 cm) long. The spatula-shaped leaves have smooth surfaces. Rose-colored, four-petaled flowers appear in loose panicles between May and August.
This fibrous rooted plant grows in small barren areas on decomposed granitic sands at elevations of 1,500-3,600 ft (457-1,097 m). It can be found in the annual grasslands and woodlands in the southwestern foothills of the Sierra Nevada Mountains.
The seven populations in six locations are estimated to occupy a total of only 14 acres (5.7 hectares) in Fresno, Madera, and Mariposa counties (California) over a range of about 40 mi (64 km). Six of the seven populations occur on private land. Five of these populations are marginal in quality and contain fewer than 300 plants. The sixth population on private land has about 900 plants. The seventh population occurs on lands administered by the Sierra National Forest and is fenced to protect it from livestock trampling and grazing.
Two populations of Mariposa pussypaws occur on lots in the midst of a subdivision. This subdivision had a vacancy rate of 23% as of March 1997; additional human impacts may occur to the two populations as the subdivision fills to 100% occupancy. A third population of Mariposa pussypaws occurs in an area including commercial and residential zoning adjacent to the location of the population. The populations of Madera and Mariposa counties (where Mariposa pussypaws occurs on private lands) were expected to increase by 58% and 55%, respectively, by 2010.
Mariposa pussypaws is threatened by urbanization. Due to the few populations and low numbers, the species is susceptible to extirpation from random events.
Conservation and Recovery
Mariposa pussypaws is found in seven occurrences; six of these are on private lands and one is in the Sierra National Forest. No other sites containing Mariposa pussypaws have been identified, and no historic locations are known. Given that targeted searches for potential habitat have been conducted, little likelihood exists of finding unknown populations within the range of the species. Only the single population occupying less than 1 acre (0.4 hectare) on U.S. Forest Service land receives federal protection. This population has been fenced to protect it from cattle trampling and grazing.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
U. S. Fish and Wildlife Service. 14 September 1998. "Determination of Threatened Status for Four Plants from the Foothills of the Sierra Nevada Mountains in California." Federal Register 63 (177): 49022-49035.