Contra Costa Goldfields
See photo info below

Sacramento Fish & Wildlife Office
Species Account

CONTRA COSTA GOLDFIELDS
(Lasthenia conjugens)

Contra Costa Goldfields
See photo info

CLASSIFICATION: Endangered Species (Federal Register 62:33029 pdf; June 18, 1997)

The California Native Plant Society has placed Contra Costa goldfields on List 1B (rare or endangered throughout its range). Although the species has not been officially listed by the State of California, the Department of Fish and Game considers it to be "very threatened."

CRITICAL HABITAT: Originally designated in Federal Register 68:46683 pdf; August 6, 2003.
The designation was revised in 70:46923 pdf; August 11, 2005. Species by unit designations were published in 71:7117 (pdf) February 10, 2006.

RECOVERY PLAN: Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon

DESCRIPTION:

Contra Costa (Lasthenia conjugens) goldfields is a showy, spring annual herb in the aster family (Asteraceae). It grows to a height of 4-12 inches and usually has an infrequently branched stem. The leaves are opposite, light green, and have a feather-like arrangement, with narrow clefts extending more than halfway toward the stem.

Yellow flowers bloom from March to June. Contra Costa goldfields can be distinguished from similar goldfields by examining the flowers. The partially fused phyllaries (floral bracts, which are reduced leaf-like structures at the base of a flower) and the lack of a pappus (a seed appendage in some species that aids dispersal by acting like a little parachute) distinguish this species from Fremont's goldfields (L. fremontii) and Burke's goldfields (L. burkei), which it otherwise closely resembles.

See Hickman (1993) in General Information about California Plants, below, for detailed information about all of these species.

DISTRIBUTION:

Contra Costa goldfields grows in vernal pools within open grassy areas in woodlands and valley grasslands from sea level to 1,500 feet. Currently, 22 populations are believed to be extant in Mendocino, Napa, Marin, Contra Costa, Alameda, Solano and Monterey counties.

See a distribution map from the draft recovery plan.

THREATS:

This species has been extirpated from Santa Barbara and Santa Clara counties by agricultural land conversion, urbanization and creek channelizing. Nearly all of the remaining populations are imminently threatened by urban development or agricultural land conversion.

REFERENCES FOR ADDITIONAL INFORMATION: (See our Disclaimer)

Crawford, J.C. and R. Ornduff. 1989. Enzyme electrophoresis and evolutionary relationships among three species of Lasthenia (Asteraceae: Heliantheae). American Journal of Botany. 76(2): 289-296.

Ornduff, R. 1976. Speciation and Oligogenic Differentiation in Lasthenia (Compositae). Systematic Botany 1(1):91-96.

U.S. Fish & Wildlife Service. 1997. Endangered and Threatened Wildlife and Plants; Endangered Status for Four Plants From Vernal Pools and Mesic Areas in Northern California. Portland, Oregon.

U.S. Fish and Wildlife Service. 2003. Endangered and Threatened Wildlife and Plants; Final Designation of Critical Habitat for Four Vernal Pool Crustaceans and Eleven Vernal Pool Plants in California and Southern Oregon Vernal pool crustaceans and plants in California and Oregon. Portland, Oregon.

U.S. Fish and Wildlife Service. 2005. Endangered and Threatened Wildlife and Plants; Final Designation of Critical Habitat for Four Vernal Pool Crustaceans and Eleven Vernal Pool Plants in California and Southern Oregon; Evaluation of Economic Exclusions From August 2003 Final Designation; Final Rule. Portland, Oregon.

U.S. Fish and Wildlife Service. 2006. Endangered and Threatened Wildlife and Plants: Designation of Critical Habitat for Four Vernal Pool Crustaceans and Eleven Vernal Pool Plants; Final Rule. Portland, Oregon.

U.S. Fish and Wildlife Service. 2005. Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon. Portland, Oregon.

General Information about California Plants

Photos of Contra Costa goldfields © 1998 by John Game Calphoto IDs: 7271 3192 3249 0064 & 7271 3192 3249 0061

Prepared by Endangered Species Div., Sacramento Fish & Wildlife Office, U.S. Fish & Wildlife Service