Search / Plant Profile / Delphinium variegatum ssp. thornei

Plant Profile

Thorne's Royal Larkspur (Delphinium variegatum ssp. thornei)

This shot shows several plants in situ. Photo Credit: Dylan Hannon

Global Rank: T1 - Critically Imperiled
Legal Status: N/A
Family: Ranunculaceae
State: CA
Nature Serve ID: 128015
Lifeform: Forb/herb
Date Inducted in National Collection: 03/08/1989

Description:

Three varieties of Delphinium variegatum are known. One, D. var. variegatum, is found along the coast and foothills of central and northern California. Another is the Federally Endangered D. var. kinkiense, or San Clemente Island larkspur, which is endemic to (found only on) San Clemente Island, one of the Channel Islands. The subspecies under the care the Center for Plant Conservation is D. var. thornei, or Thorne's larkspur. This subspecies is also endemic to San Clemente, and also considered rare, even more so than the San Clemente Island larkspur. However, this rarest subspecies has no special legal status, although the U.S. Fish and Wildlife Service considers it to be a species of concern. The San Clemente Island larkspur occurs mainly on the northern end of the island, while Thorne's larkspur occurs mainly on the south. However, the two rare subspecies of San Clemente Island have been the subject of recent study, because there is considerable overlap in their ranges. To date, the only way to consistently distinguish one from the other is by sepal color, with Thorne's larkspur having light blue to bright blue flowers and the endangered San Clemente Island larkspur having white to light blue flowers. Populations that occur in the center of the island have individual plants with white, bright blue, and intermediate flower colors, suggesting that the two subspecies may be hybridizing. (Dodd and Helenurm 2000, 2002)

Where is Thorne's Royal Larkspur (Delphinium variegatum ssp. thornei) located in the wild?

Habitat:

Open grassy hills and woods

Distribution:

Delphinium variegatum ssp. thornei (Thorne's royal larkspur) is restricted to southern San Clemente Island. (Dodd and Helenurm 2002)

States & Provinces:

Thorne's Royal Larkspur can be found in California

Which CPC Partners conserve Thorne's Royal Larkspur (Delphinium variegatum ssp. thornei)?

California Botanic 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, California Botanic Garden holds 2 accessions of Delphinium variegatum subsp. thornei in orthodox seed collection. There are as many as 1460 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, California Botanic Garden has collected 2 seed accessions of Delphinium variegatum subsp. thornei from 2 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass 2 maternal plants

Nature Serve Biotics

05/02/2017

Restricted to San Clemente Island, California; small number of sites on the island, may be highly threatened by feral animals.

01/01/2010

The recent removal of goats from the island has removed the only known threat to this species. (USFWS 1996)

01/01/2010

Roughly 13,000 individuals are known from 13 populations. (USFWS 1996)

01/01/2010

Recent and ongoing research has been performed on Delphinium variegatum and its three subspecies (var. variegatum, var. kinkiense, var. thornei). Research includes floral variation and genetic diversity. (Dodd and Helenurm 2000, 2002)

01/01/2010

The U.S. Navy has jurisdiction over San Clemente Island, has an ongoing program to remove feral goats and pigs in an effort to restore the native vegetation. (CDFG 2002)

01/01/2010

Keep feral goats and pigs out of populations of this species. Ensure that invasive species are kept in check on San Clemente Island.

01/01/2010

Maintain a genetically representative seed bank.