Coyote Ceanothus

Ceanothus ferrisiae

Description

Coyote ceanothus, Ceanothus ferrisiae, is an erect evergreen shrub of the buckthorn family (Rhamnaceae) that grows 3-6 ft (0.9-1.8 m) high, with long stiff divergent branches. Its round leaves are dark green and hairless on the upper surface, and lighter green with minute hairs below. The leaf margins have short teeth or sometimes no teeth at all; the leaf base is abruptly tapering or rounded. The small white flowers are borne in clusters 0.5-1.0 in (1.3-2.5 cm) long. The seed capsules are 0.3-0.35 in (0.8-0.9 cm) in width and have three conspicuous apical horns. The related C. cuneatus has entire leaves with wedge-shaped bases and seed capsules only 0.2 in (0.5 cm) wide.

Coyote ceanothus is perennial, flowering from January to March. The three populations show no evidence of seedling recruitment, and all of the populations are composed of mature and senescent individuals. Coyote ceanothus seeds do not apparently require fire for germination. If the seeds do not require fire for germination, the lack of recruitment in natural populations may be due to seed or seedling mortality. Possible sources of mortality include seed predation, grazing/browsing, lack of sufficient precipitation to maintain young plants through the dry summer following germination, or some combination of these. Despite the results of the germination studies, the only seedlings observed in nature followed a fire in Kirby Canyon. Maintenance of a healthy population of coyote ceanothus may require some prescription burning.

The coyote ceanothus population in Kirby Canyon, the smallest of the three populations, burned during the summer of 1992. Approximately 5% of the several hundred individuals survived the fire. All of the surviving individuals were damaged by the fire and supported only one to several live branches at the time of a census in December 1992. Although flower buds were present and apparently in good condition, potential seed production in the population was severely reduced. Despite sufficient precipitation for germination, no seedlings were observed in 1992. However, during the following spring approximately 2,000 seedlings were observed. These seedlings were fenced to protect them from grazing until the plants were established. In addition, because the fence did not prevent deer and rabbit grazing, 100 plants were individually caged. One year later survivorship of the caged seedlings was good.

Habitat

Coyote ceanothus grows on dry slopes in serpentine chaparral and valley and foothill grassland below 1,000 ft (305 m). Rare species associated with coyote ceanothus include the federally listed bay checkerspot butterfly and Santa Clara Valley dudleya as well as most beautiful jewelflower and Mt. Hamilton thistle, two species of concern.

Distribution

Coyote ceanothus is known from only three locations: Anderson Dam, Kirby Canyon, and Llagas Avenue north of Morgan Hill. All the locations are within four miles of each other in Santa Clara County. The Anderson Dam location includes two of the populations in the California Natural Diversity Data Base, Kirby Canyon is one population, and Llagas Avenue north of Morgan Hill is one population. The Anderson Dam populations may have been continuous before the dam was built. Coyote ceanothus has not been observed in Croy Canyon in Santa Clara County, a fifth population in California Natural Diversity Data Base records, since 1929, and the location is possibly erroneous. The species was also thought to occur in San Mateo and Santa Cruz counties, but these reports are thought to be erroneous. Fewer than 6,000 plants are known to exist.

Threats

The existing populations of coyote ceanothus are threatened by residential and recreational development, unauthorized dumping, landfill activities, lack of natural recruitment, altered fire regimes, grazing, and stochastic events. The largest population, consisting of approximately 5,000 plants, occurs near Anderson Dam, partially on Santa Clara County Park property and partially on private property. The Santa Clara Valley Water District has an easement for a small area of the County's portion of the Anderson Dam population. Several dozen plants were removed when the Santa Clara Valley Water District enlarged the spillway to Anderson Dam. Two more plants were transplanted as a result of emergency work on the spillway in January 1997. Coyote ceanothus at the Anderson Dam site is also threatened by grazing and unauthorized dumping of litter and larger debris. Dumping can degrade or threaten a habitat by directly killing the plants, depriving them of light or disturbing the soil, thus promoting erosion and invasion of weedy, competitive species.

The Kirby Canyon population, which occurs two miles west of Anderson Dam, is on property leased and managed by Waste Management of California, Inc. A portion of this population was proposed to be destroyed for construction of sedimentation ponds as part of landfill activities, but that was not done, and there are no plans to do so. This population is also threatened by cattle grazing and dumping. The third population, consisting of approximately 500 plants, occurs on private land. Although coyote ceanothus still exists at the site, a portion of the population had been developed as of April 1997. A portion may be set-aside in a city or county easement. When the site was last visited, the plants seemed to be rather senescent and all of the same age class.

Conservation and Recovery

Coyote ceanothus is relatively easy to propagate from seed and from tip cuttings as well. The species may be propagated in nurseries, and several large shrubs were growing in the Tilden Botanic Garden at the turn of the twenty-first century.

Both Waste Management and the Santa Clara Valley Water District have experimented with the use of coyote ceanothus for revegetation projects, and, in 1993, the Santa Clara Valley Water District launched a revegetation project. In 1997, when emergency work along the spillway was necessary, the Water District transplanted two shrubs to a location approximately 20 ft (6 m) away. In May 1997, the plants had been browsed, but no disease, insect damage, or vandalism were evident.

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. 1998. "Recovery Plan for Serpentine Soil Species of the San Francisco Bay Area." U. S. Fish and Wildlife Service, Portland. 330+ pp.