Regularity: Regularly occurring
Comments: Sheer volcanic cliffs and canyon walls in canyons with perennial streams. Usually grows with mosses and lichens in places too steep for soils to form.
National NatureServe Conservation Status
Rounded National Status Rank: N2 - Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: T2 - Imperiled
Reasons: Restricted to an unusual microhabitat and known with certainty only from an area about 24 km long in the Santa Monica Mountains of southern California. There are 7 known occurrences. The total number of individuals is estimated to be less than 1000. Threats include unsupervised rock climbing and boulder hopping.
Date Listed: 01/29/1997
Lead Region: California/Nevada Region (Region 8)
Listing status: T
For most current information and documents related to the conservation status and management of Dudleya cymosa marcescens, see its USFWS Species Profile
Comments: Major threats to Dudleya cymosa ssp. marcescens are rock climbing and rappelling, other recreational activities (such as damage from informal climbing, boulder hopping, and substrate removal at gathering sites), and residential development (half of the occurrences are on private lands) (USFWS 2009). Other threats are conversion of private land to agriculture, horticultural collection, and wildfires which tend to burn much more widely and intensely than Dudleya cymosa ssp. marcescens is adapted to (USFWS 2009). Climate change is also listed as a possible threat but the extent of this threat is not yet known (USFWS 2009).
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