Dudleya parva Rose & Davidson:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Historic Range:
U.S.A. (CA)

Isotype for Dudleya parva Rose & Davidson
Catalog Number: US 1319816
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): J. Bullard
Year Collected: 1922
Locality: Bank of Conejo Grande., California, United States, North America

Isotype for Dudleya parva Rose & Davidson
Catalog Number: US 1319812
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): J. Bullard
Year Collected: 1922
Locality: Bank of Conejo Grande., California, United States, North America

Comments: Clays at the base of scattered rock outcrops of the Conejo volcanics in grassland or coastal sage scrub vegetation.

United States

Rounded National Status Rank: N2 - Imperiled

Rounded Global Status Rank: T2 - Imperiled

Reasons: Restricted to a specific volcanic substrate in the mountains forming the western boundary of the Los Angeles Basin, California. The total range is about 16 km long. There are 11 populations, most numbering in the hundreds of individuals. Threats include hiking and horseback riding, urban development, and fire suppression.

Current Listing Status Summary

Status: Threatened
Date Listed: 01/29/1997
Lead Region:   California/Nevada Region (Region 8) 
Where Listed:


Population detail:

Listing status: T

For most current information and documents related to the conservation status and management of Dudleya abramsii parva, see its USFWS Species Profile

Comments: The major threats to Dudleya abramsii ssp. parva are urban and recreational development (USFWS 2009). This includes equestrian facilities and activities, recreational activity (mountain biking, off-road vehicles, hiking, rock climbing, and horseback riding), and fire suppression activities that invite non-native annuals that outcompete Dudleya abramsii ssp. parva (USFWS 2009).

Other threats include naturally caused events (such as drought, disease, or rock slides) due to Dudleya abramsii ssp. parva's restricted range and the small population size, especially wildfires which tend to burn much more intensely than the type of fire this taxon is adapted to (USFWS 2009). It is possible that horticultural collection may be a threat as well (USFWS 2009).

Predation by an unknown native caterpillar has been reported in many locations, but is not necessarily considered a threat currently (USFWS 2009). Likewise, climate change is also listed as a possible threat but the extent of this threat is not yet known (USFWS 2009).