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Plant Profile

Vine Hill Clarkia (Clarkia imbricata)

A closeup of the large pink flowers of this species. Photo Credit: Roger Raiche

Global Rank: G1 - Critically Imperiled
Legal Status: Federally Endangered
Family: Onagraceae
State: CA
Nature Serve ID: 138502
Lifeform: Forb/herb
Date Inducted in National Collection: 03/08/1989

Description:

Vine Hill clarkia is a late-blooming, slender annual herb with large white or pinkish flowers. This species grows in habitats with sandy loam soils. Historically, it is known from only two natural occurrences in the Vine Hill area of Sonoma County, California. One of these is extirpated, leaving a single native population. A transplanted population exists at the California Native Plant Society's one-acre Vine Hill Preserve (CDFG 2002).

Where is Vine Hill Clarkia (Clarkia imbricata) located in the wild?

Habitat:

Chaparral, valley and foothill grasslands in acidic sandy loam soils (Skinner 1997).

Distribution:

Historically, it is known from only two natural occurrences in the Vine Hill area of Sonoma County. One of these is extirpated, leaving a single native population. A transplanted population exists at

States & Provinces:

Vine Hill Clarkia can be found in California

Which CPC Partners conserve Vine Hill Clarkia (Clarkia imbricata)?

California Botanic Garden

Not Sponsored

Conservation Actions

Assigned 06/09/17

University of California Botanical Garden

Not Sponsored

Conservation Actions

Assigned 06/09/17

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

09/01/2020

Based on an September 2020 extract of the California Plant Rescue Database, University of California Botanical Garden holds 1 accessions of Clarkia imbricata in orthodox seed collection. We are uncertain as to how many total seeds are in this collection.

09/01/2020

Based on an September 2020 extract of the California Plant Rescue Database, California Botanic Garden holds 4 accessions of Clarkia imbricata in orthodox seed collection. There are as many as 13817 seeds of this species in their collection - although some may have been used for curation testing or sent to back up.

08/05/2020

Based on an August 2020 extract of the California Plant Rescue Database, University of California Botanical Garden has collected 1 seed accessions of Clarkia imbricata from 1 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass an unknown number of maternal plants

Holly Forbes

08/30/2017

Proposed land use conversion Inadequate regulatory mechanisms Stochastic events Damage associated with trespassers collecting other rare plants Unauthorized collection

Nature Serve Biotics

05/02/2017

Narrowly endemic to a small area in Sonoma County, California. Historically, four populations were known; currently, there is one natural population, with a total of about 5000 plants, and one planted population with < 400 plants. One historic population may have been extirpated by roadside maintenance; the other was extirpated by Christmas tree farming and weed control activities. The natural population is potentially threatened by conversion to agriculture or other land use change. Unauthorized collection is also a threat.

Holly Forbes

01/01/2010

Vine Hill Clarkia is currently known from two populations in southern Sonoma County, California, one natural and one planted in a reserve. The natural population contains 2,000 to 5,000 plants; the planted population has fluctuated between 200 and 300 plants.

Holly Forbes

01/01/2010

None at this time.

Holly Forbes

01/01/2010

The native population of Vine Hill clarkia was formerly split between two privately owned parcels. Until several years ago, The Nature Conservancy had cooperative agreements with both landowners to protect the population. Since then, the soil on one of the parcels was scraped, and the plants there have been extirpated. The other parcel was sold in 1997 and a portion of the Vine Hill clarkia habitat on this second parcel was disturbed. Plants may not reestablish on the disturbed soil based on prior observations that the plant depends on the presence of an undisturbed soil crust. The new landowner wants to build on the plant's habitat, but is willing to sell the parcel instead. The California Department of Fish & Game is seeking cooperation to protect this last remaining portion of the native population of Vine Hill clarkia (CDFG 2002).

Holly Forbes

01/01/2010

Additional information is needed to identify suitable sites for reintroduction as well as for vegetation management.

Holly Forbes

01/01/2010

Additional seed collection for long-term storage is desirable.