Springville Clarkia

Clarkia springvillensis

Description

Springville clarkia, Clarkia springvillensis, is an erect annual herb in the evening primrose family (Onagraceae). The 3 ft (1 m) tall plant has simple or usually branched stems. The bright green leaves are 0.8-3.5 in (2-9 cm) long and 0.2-0.8 in (0.5-2 cm) broad. The lavender-pink flowers appear in May to July and usually have a dark purplish basal spot. Springville clarkia can be separated from the co-occurring C. unguiculata by the absence of long hairs on the calyx and ovary, the purple sepals, and the dark purplish spot at the base of the petals.

Habitat

Springville clarkia is found on granitic soils in sunny sites from 1,220 to 3,000 ft (372 to 914 m) in elevation. Springville clarkia grows mostly on the uphill slope of roadbanks, on small decomposing granitic domes, and in openings within the blue oak woodland community in the foothills of the southern Sierra Nevada Mountains of Tulare County, where 15 populations occur.

Distribution

Collectively, the populations are estimated to occupy a total of 150 acres (60.7 hectares). All but one of the 15 populations are found within about a 15-mi (24-km) range, with the remaining population 16 mi (25.7 km) to the northwest. One site is partially protected by the California Department of Fish and Game, one is on Bureau of Land Management land, eight are on U.S. Forest Service land, and five are on private land. With the variability typical of an annual plant, six populations of Springville clarkia have ranged from 20 to 200 plants. Four populations along roadsides have become restricted to a narrow band just above a zone of herbicide use and just below heavily grazed terrain. The largest population of this plant occurs on the 4.5-acre (1.8-hectare) preserve owned by the California Department of Fish and Game.

Threats

Springville clarkia is threatened by urban development, inadequate regulatory mechanisms, heavy livestock grazing, and roadway maintenance activities. Due to the small numbers of populations and individuals, Springville clarkia is vulnerable to extirpation from random events.

Two populations of Springville clarkia on the Sequoia National Forest and three populations on non-Federal lands are threatened by road maintenance activities such as grading and roadside mowing. These five populations comprise more than 40% of the known acreage of Springville clarkia habitat. Four of these five populations are small and have become restricted to a narrow band above and/or below the part of the roadbank that is not graded and above and/or below the heavily grazed terrain across a fence adjacent to the roadway. Mowing usually occurs when the grass turns golden, just when Springville clarkia begins to flower. One of the five sites is along a county road that is graded infrequently by the Tulare County Public Works Department; the plants extend to the edge of the road and are graded and buried periodically. At this same site, Springville clarkia appears to be threatened by the Public Works Department dumping of sand.

A sixth population of Springville clarkia, on private land, is threatened by development. Zoning in portions of the area allows one dwelling per 2.5 acres (1 hectare) as long as the dwellings are occupied by family, employees, or farm laborers. This is in addition to an allowance for one dwelling for the owner. Further subdivision of parcels requires an amendment to the general plan. Applications for general plan amendments can be submitted whenever, and as frequently as, the land owner wishes in Tulare County. Three small populations of Springville clarkia occur on lands owned by Tulare County. These populations are subject to incidental impacts associated with frequent large nature group walks and livestock grazing.

The largest population of Springville clarkia occurs on a 4.5-acre (1.8-hectare) preserve owned by the California Department of Fish and Game. Prior to acquisition by the California Department of Fish and Game, this property had an access road cut into the preserve, a water well drilled, and a knoll leveled as a pad for home construction. The type locality for Springville clarkia, which covers a 67-acre (27-hectare) area, was extirpated by mobile home development.

The only other known Springville clarkia population was extirpated by mobile home development in 1983; the species has not been relocated at the site because the habitat for the species is no longer present.

Conservation and Recovery

Springville clarkia is found in 15 occurrences. Eight of these occurrences are on U.S. Forest Service lands and one is on Bureau of Land Management lands. The remainder are on non-Federal lands, including private, County, and State lands. Prior to listing the species, the U.S. Fish and Wildlife Service conducted extensive public outreach. On Federal lands, modification of occupied habitat is unlikely because the presence of Springville clarkia, and its specific locations, are well-known to the managers of the Sierra National Forest and to the managers of the Bureau of Land Management lands where the species occurs. The Sierra National Forest has written a species management guide for populations of Springville clarkia that occur on Federal lands. Likewise, the Bakersfield Bureau of Land Management office is aware of the single population of Springville clarkia which occurs on Federal land administered by that agency. Additionally, the Caliente Resource Area Management Plan coveres many current and proposed land use actions, including those in Tulare County, which may affect Springville clarkia.

Contact

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
http://pacific.fws.gov/

Reference

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 61 (177): 49022-49035.