Search / Plant Profile / Arabis mcdonaldiana

Plant Profile

Red Mountain Rockcress (Arabis mcdonaldiana)

Arabis macdonaldiana in bloom. Photo Credit: Veva Stansell

Global Rank: G3 - Vulnerable
Legal Status: Federally Endangered
Family: Brassicaceae
State: CA, OR
Nature Serve ID: 132067
Lifeform: Forb/herb
Date Inducted in National Collection: 03/14/1986

Description:

The small crimson to purple flowers of Arabis macdonaldiana are both beautiful and fragrant (Eastwood 1903). This interesting little plant was discovered in northern Mendocino County, California in 1902, and described as a distinct species the following year. Its discoverer was Alice Eastwood, one of the earliest and most well known female botanists. It was not identified in Oregon until 1980, a year after its listing as endangered with the Fish and Wildlife Service (Meinke 1982). Arabis macdonaldiana was the second plant species to be listed as endangered by the US Fish and Wildlife Service (September 1978). As the time of listing, only one population of A. macdonaldiana was known, and it was in imminent danger of being destroyed by nickel mining. Today, because of the discovery of additional populations in California and Oregon as well as some complex taxonomic changes, there are many populations of A. macdonaldiana known. Despite the fact that there are many more populations known than when it was originally listed, the species is still in grave danger. The large number of populations may make the species eligible for down-listing or de-listing. This may sound like a great accomplishment. However, populations are still small and still at great risk from mining activities and other human caused disturbances. As many of the known sites are on National Forest land, their listing as Endangered by the Fish and Wildlife Service is one of few protective measures keeping nickel mining from destroying them and their habitat.

Where is Red Mountain Rockcress (Arabis mcdonaldiana) located in the wild?

Habitat:

Serpentine barren habitat, usually on steep unstable slopes or dry open woods below 4900 ft (1500m). Most areas are recently disturbed, exposing less weathered serpentine soil. Canopy cover is generally less than 3%.

Distribution:

CA, ORRanges: CA: NcoRO (Klamath -Siskiyou Region)OR: Klamath Mountains

States & Provinces:

Red Mountain Rockcress can be found in California, Oregon

Which CPC Partners conserve Red Mountain Rockcress (Arabis mcdonaldiana)?

Rae Selling Berry Seed Bank & Plant Conservation Program

Not Sponsored

Conservation Actions

Assigned 06/09/17

California Botanic Garden

Not Sponsored

Conservation Actions

Assigned 01/17/19

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 1 accessions of Arabis mcdonaldiana in orthodox seed collection. There are as many as 5243 seeds of this species in their collection - although some may have been used for curation testing or sent to back up.

09/01/2020

Based on an September 2020 extract of the California Plant Rescue Database, Rae Selling Berry Seed Bank & Plant Conservation Program holds 8 accessions of Arabis mcdonaldiana in orthodox seed collection. There are as many as 5353 seeds of this species in their collection - although some may have been used for curation testing or sent to back up.

08/18/2020

Taxonomic studies to investigate the relationship between California and Oregon populations. Results not published as of 2001 (Linda Ann Vorobik-UC Berkeley).

08/18/2020

Germination studies at the Berry Botanic Garden. Both 8 weeks of cold stratification followed by 68F (20C) and direct 68F (20C) treatments resulted in 100% germination (BBG file).

08/18/2020

Seeds stored in BBG seed bank from collections in 1987 and 1989. All collections are from Mendocino and Del Norte Counties in California. No seeds are stored from Oregon populations. All collections are bulked- there is no separation of maternal lines (BBG File)

08/18/2020

08/05/2020

Based on an August 2020 extract of the California Plant Rescue Database, Rae Selling Berry Seed Bank & Plant Conservation Program has collected 8 seed accessions of Arabis mcdonaldiana from 2 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass 43 maternal plants

Nature Serve Biotics

05/02/2017

Restricted to serpentine areas and known from 30-40 sites in northern California (Mendocino, Del Norte and Siskiyou counties) and immediately adjacent southwestern Oregon. Some populations are threatened by mining of the nickel-rich soils of its habitat and encroachment of woody vegetation. Many sites are on USFS lands, but none may be in permanent protection.

Edward Guerrant, Ph.D.

01/01/2010

Slope erosion, road maintenance, and logging. Succession Proposed construction and mining for nickel (Nicore Corporation) 1997/98/99 Over-collection (Meinke 1982) Off-road vehicle use

Edward Guerrant, Ph.D.

01/01/2010

In Oregon, 2() extant populations with few individuals (ONHDB 2000). In California, 29 sites ""presumed extant"" with numbers ranging from ""a few"" to approximately 5,000 (CNDDB 2000). Many sites have not been surveyed since the mid 1980's, so numbers may not be accurate, and many sites that were reported as declining may in fact have been extirpated by now.

Edward Guerrant, Ph.D.

01/01/2010

Germination studies at the Berry Botanic Garden. Both 8 weeks of cold stratification followed by 68F (20C) and direct 68F (20C) treatments resulted in 100% germination (BBG file). Taxonomic studies to investigate the relationship between California and Oregon populations. Results not published as of 2001 (Linda Ann Vorobik-UC Berkeley). Determination and search for potential habitat using Landsat Thematic Mapper imagery to locate serpentine barren habitat (Daniel and Fox 1999).

Edward Guerrant, Ph.D.

01/01/2010

One population is located on land designated as a ""Botanical Wayside"". The area was established in 1938 to serve as an interpretive and educational resource for local agencies, organizations, and schools (CaveJunction.Com 2002). Seeds stored in BBG seed bank from collections in 1987 and 1989. All collections are from Mendocino and Del Norte Counties in California. No seeds are stored from Oregon populations. All collections are bulked- there is no separation of maternal lines (BBG File) Known Oregon sites are on National Forest Land.

Edward Guerrant, Ph.D.

01/01/2010

Search for additional populations in Oregon and California (Meinke 1982) Protect any newly discovered populations (Meinke 1982) Limit land access and use (Daniel and Fox 1999). Determine soil variables associated with A. macdonaldiana presence (Daniel and Fox 1999) Determine how variables such as percent moss cover, percent rock, or microposition are correlated to species' occurrence (Daniel and Fox 1999). Determine how tree, shrub, herb or grass cover correlate with presence of species (Daniel and Fox 1999).

Edward Guerrant, Ph.D.

01/01/2010

Collect and store seeds from representative populations in both Oregon and California. Keep maternal lines separate during collection. Determine propagation and reintroduction protocols.