Overview
Santa Clara Valley dudleya is a low-growing perennial succulent with pale yellow flowers that grows in rocky outcrops in serpentine grasslands and is found only in the Coyote Valley area of Santa Clara County, California, from San Jose south about 25 miles to Gilroy. The species occurs on rock outcrops in serpentine grasslands between 390 to 990 feet in elevation. At the time of listing in 1995, the Santa Clara Valley dudleya was known from fourteen sites. Currently there are 59 known occurrences.
Threats to the species include:
- Residential development
- Infrastructure maintenance activities
- Quarry expansion
- Unauthorized dumping
- Off-road vehicles
- Fragmentation
- Non-native invasive plants exacerbated by atmospheric nitrogen deposition from vehicle exhaust
- Inappropriate levels of grazing
- Herbivory by rodents (e.g. ground squirrels, rabbits)
- Feral pigs
- Collection
- Climate change
- Catastrophic wildfire
- Change of land management due to urban development
The majority of the occurrences of the Santa Clara Valley dudleya have been protected under the reserve system for the Santa Clara Valley Habitat Conservation Plan/Natural Communities Conservation Plan which has removed some of the threats from development.
Santa Clara Valley dudleya was listed as endangered on February 3, 1995.
Scientific Name
Identification Numbers
Characteristics
Life Cycle
Santa Clara Valley dudleya flowers from May to June and produces wind dispersed seeds. The species can also reproduce vegetatively by forming rosettes that can separate from the parent plant or remain attached.
Individual plants may live for approximately 10 years.
Physical Characteristics
Santa Clara Valley dudleya is a low-growing perennial of the stonecrop family with fleshy, hairless leaves. The oblong to triangular leaves are covered with a whitish or bluish waxy or powdery film. The leaves are 1 to 3 inches long and 0.3 to 0.6 inch wide. Two or three flowering stems ascend to heights of 2 to 8 inches in mid- to late spring. The pale yellow petals are 0.3 to 0.5 inch long.
Habitat
Santa Clara Valley dudleya is restricted to rocky outcrops within serpentine grasslands between 390 to 990 feet in elevation in Santa Clara County, California. The roots are at least 6 inches long and often extend into rock crevices of the serpentine outcrops.
Land on which the natural dominant plant forms are grasses and forbs.
Timeline
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