Loch Lomond Coyote-thistle

Eryngium constancei

Description

Despite its name, Loch Lomond coyote-thistle, Eryngium constancei, is not a thistle but a perennial herb of the parsley family. It annually produces many slender scapes (leafless flowering stalks) up to 12 in (30 cm) high from an overwintering root-stock. Narrow, grasslike blades, up to 8 in (20 cm) long, are attached to the base of the plant by slender petioles that bear small spines. Flowers are sparse and undistinguished. A dense covering of minute hairs on the leaves distinguishes the Loch Lomond coyote-thistle from all other species within the genus. Germination occurs after the winter rains have begun sometime after November; flowering occurs June to July; and fruiting probably occurs in the fall.

Habitat

Loch Lomond coyote-thistle grows in a vernal lake basin that is underlain by a powdery, clay soil of volcanic derivation. This seasonal wetland is bordered on two sides by stands of ponderosa pine and California black oak. The southern and eastern portions of the lake are bounded by a paved road and a row of summer cabins.

Habitat requirements are not specifically known, but botanists believe that the length of time the vernal pool is filled, the pattern of rainfall throughout the winter months, and the temperature of the water may be decisive in establishing the amount of germination, mortality, flowering, and seed set for this species.

When waters evaporate from the basin in summer, it becomes a meadow-like area. Associated plants include spikerush, downingia, and allocarya. Two other rare plants—few-flowered navarretia (Navarretia pauciflora ) and many-flowered navarretia (N. plieantha )—occur in the same basin and are candidates for federal listing. The lake bed is at an elevation of 2,800 ft (840 m).

Distribution

Loch Lomond coyote-thistle is probably endemic to the region south of Clear Lake in Lake County, California. Currently, it is restricted to the bed of a shallow 7-acre (2.8-hectare) vernal lake near the community of Loch Lomond (Lake County), California. An intensive search in 1984 failed to locate additional colonies of this plant. No population figures were published, but numbers are very low. Botanists who have studied the species believe that additional populations are unlikely to exist because of the specificity of the habitat requirements.

Threats

In 1985 about 15% of the wetlands were illegally dredged and filled to protect surrounding houses from seasonal flooding. A shallow drainage ditch dug through the center of the lake reduced its storage capacity, further restricting the plant's range. Because proper permits were not secured, the landowner was fined and instructed by the state to restore the lake bed. The landowner complied, grading the site to its former contours, but at the same time expressed his intention of securing permits to continue his project of draining the lake.

Conservation and Recovery

Because of the imminent threat of loss of habitat, the U. S. Fish and Wildlife Service proposed Loch Lomond coyote-thistle for emergency protection under the Endangered Species Act. When this temporary status expired in 1986, the species was granted full Endangered status on the federal list.

In addition to state and county permits, dredging and filling of wetlands requires a permit from the U. S. Army Corps of Engineers to comply with the Clean Water Act. These permits can be denied if such an operation jeopardizes the survival of a federally listed plant. When a landowner refuses to cooperate with attempts to conserve a plant, as in this case, denying a permit for wetlands alteration is only a temporary solution. Loch Lomond coyote-thistle will probably need to be cultivated and then transplanted to other suitable locations where it can be more readily protected and where the habitat can be managed to benefit the species.

Contact

Regional Office of Endangered Species
U.S. Fish and Wildlife Service
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232
http://pacific.fws.gov/

References

Crane, N. L., and B. S. Malloch. 1985. "A Study of the Rare Plants for the Geysers-Calistoga Known Geothermal Resources Area." Report. Pacific Gas and Electric Company.

Sheikh, M. Y. 1983. "New Taxa of Western North American Eryngium (Umbelliferae)." Madroño 30:93-101.

U.S. Fish and Wildlife Service. 1986. "Determination of Endangered Status for Erynigum constancei." Federal Register 51: 45904-45907.