Santa Ana River Woolstar (Eriastrum densifolium ssp. sanctorum)

This shot shows the plants, highlighting the distinctive blue flowers. Photo Credit: Michael Wall

Global Rank: T1 - Critically Imperiled
Legal Status: Federally Endangered
Family: Polemoniaceae
State: CA
Nature Serve ID: 161697
Lifeform: Forb/herb, Subshrub
Date Inducted in National Collection: 03/14/1986

Description:

This endangered blue-flowered phlox species is restricted to sandy floodplain areas in Southern California and was listed as Federally Endangered in 1987. Remaining populations are threatened by flood control and competition with a non-native species, river cane (Arundo donax). In 1988, a preservation area was established by the U.S. Army Corps of Engineers in an undeveloped portion of land in San Bernardino National Forest that includes 309 hectares (764 acres) of suitable habitat for Eriastrum densifolium ssp. sanctorum. The biggest threat to this species is the construction of the Seven Oaks dam, which is currently in progress, which will substantially reduce the historic floodplain areas that this species lives on. This shrub can grow to one meter (3.3 feet) tall, with gray-green stems and leaves. It produces bright blue flowers that are up to 1.4 inches long that occur in flower heads with about 20 blossoms each. (USFWS 1986)

Where is Santa Ana River Woolstar (Eriastrum densifolium ssp. sanctorum) located in the wild?

Habitat:

Sandy river floodplain along the Santa Ana River in California. This alluvial fan supports another Center for Plant Conservation taxon, the slender-horned spineflower (Dodecahema leptoceras). (CDFG 2002)

Distribution:

Endemic to the Santa Ana River Drainage in San Bernardino and Riverside County in southern California.

States & Provinces:

Santa Ana River Woolstar can be found in California

Which CPC Partners conserve Santa Ana River Woolstar (Eriastrum densifolium ssp. sanctorum)?

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

09/09/2020

Anatomical features of Eriastrum densifolium subspecies from populations in Southern California have shown variation in their morphological features that correlate with their specific habitats and can be used in differentiating subspecies (Brunell and Whitkus 1997, 1998). When crossed with other Eriastrum species, Eriastrum densifolium ssp. sanctorum showed exhibited a high infertility rate (Brunell and Whitkus 1999). Graduate students have studied a number of subjects relating to this species (Phommasaysy 1999, Brunell 1996, Stone 1995, Erickson 1994, Wheeler 1991, Munoz 1991, Brunell 1991)

09/01/2020

Based on an September 2020 extract of the California Plant Rescue Database, California Botanic Garden holds 5 accessions of Eriastrum densifolium subsp. sanctorum in orthodox seed collection. There are as many as 82985 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 4 seed accessions of Eriastrum densifolium subsp. sanctorum from 1 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass 760 maternal plants

Nature Serve Biotics

05/02/2017

Eriastrum densivolium ssp. sanctorum is endemic to the Santa Ana River drainage of San Bernardino, Riverside and Orange Counties. Extirpated in Orange County, the beautiful perennial with large lavender flowers is known from several fragmented, damaged occurrences. Intensive use of the flood plain margins has resulted in alteration of habitat and habitat that is totally unsuitable. The Santa Ana River woollystar is also threatened by development, sand and gravel mining, flood control projects, non-native plant competition, intensive grazing, and farming. There are no protected EO's to speak of. The overall trend is very much downhill.