Monterey Clover

Trifolium trichocalyx

Description

The Monterey clover is a widely branching, prostrate, annual herb with branches as long as 8-12 in (20-30 cm). Its compound leaves are composed of three obovate-cuneate leaflets, 0.2-0.5 in (0.4-1.2 cm) long, and truncate or shallowly notched at the end. The numerous flowers are clustered into heads subtended by long-toothed bracts. The calyx bracts are 0.3 in (7 mm) long, toothed, and conspicuously long-hairy. The purple corolla elements are similar in length to the calyx. The seed pods are deciduous and contain as many as seven seeds.

Habitat

The Monterey clover occurs in openings within Monterey pine (Pinus radiata ) forest on poorly drained soils consisting of coarse loamy sands. Occasional, light wildfire is necessary to maintain the open conditions needed by this rare plant.

Distribution

The Monterey clover is only known from one area, Huckleberry Hill, covering about 40 acres (16 hectares) on the Monterey Peninsula, California.

Threats

The total area of Monterey pine forest has decreased tremendously, due to conversion to agricultural, commercial, and residential development. On the Monterey Peninsula itself, most forest loss has been associated with the development of a golf course and its associated infrastructure. The first collection of the Monterey clover was made in 1903, two years after a fire in its habitat. Other surveys in 1973, 1979, and 1980 found only scattered individuals in forest openings or edges. One of these sites was extirpated when Poppy Hills Golf Course was developed in 1980. The other two are within the boundaries of the Morse Reserve. Another survey in 1988 found no plants in previously known sites, but discovered a population of several hundred to one thousand plants in a 200-acre (80-hectare) habitat that had burned in 1987, near Huckleberry Hill. Surveys of that burned area in 1996 found only 22 plants, although it is likely that a persistent seed-bank occurs in the soil. Ongoing threats to Monterey clover include the suppression of the natural fire cycle, and a proposed golf-course development within the largest area known to support the rare plant clover in 1988. Because of the small area of its habitat and tiny population, the Monterey clover is also potentially threatened by unpredictable catastrophes, such as an extreme weather event.

Conservation and Recovery

Conservation of the Monterey clover requires that its habitat be preserved, and that periodic wildfire continues. This disturbance is necessary to create conditions suitable for the germination of the persistent seedbank of the rare clover, and is critical to its survival. The known surviving habitat of the Monterey clover must be protected against further incursions by private development. This will require the acquisition of the land and establishment of an ecological reserve, or the negotiation of conservation easements. Research is also needed into the biology and ecological requirements of the Monterey clover, and into means of its cultivation in captivity. The latter is required to produce stock to be used for the establishment of additional wild populations, and to guard against the potential of extinction of the few known natural populations.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

Ventura Fish and Wildlife Office
U. S. Fish and Wildlife Service
2493 Portola Road, Suite B
Ventura, California 93003
Telephone: (805) 644-1766
Fax: (805) 644-3958

Reference

U. S. Fish and Wildlife Service. 12 August 1998. "Endangered and Threatened Wildlife and Plants: Final Rule Listing Five Plants From Monterey County, CA, as Endangered or Threatened." Federal Register 63 (155):43100-43116.