The following Participating Institutions are custodians for this species in the CPC National Collection:
Rancho Santa Ana Botanic Garden
The conservation of Thelypodium stenopetalum is fully sponsored.
Naomi Fraga contributed to this Plant Profile.
Thelypodium stenopetalum is a biennual herb in the mustard family (Brassicaceae) endemic to the San Bernardino Mountains, San Bernardino County, California. This species has linear shaped lavender petals that bloom between March and August. The flowering stems are not produced until the second or third year of growth (CNPS 2007). Thelypodium stenopetalum was listed as endangered in 1998. Two occurrences have been extirpated and the eight remaining occurrences at the southwest end of Erwin Lake and the southwest end of Big Bear Lake have not been documented recently and have either been degraded or extirpated.
Distribution & Occurrence
Thelypodium stenopetalum occurs in vernally wet meadows, alkaline flats, and lakeshores at elevations of 6,470-7,430 ft (2,054-2,237 m). Plants of this species tend to occupy drier sites within meadows in areas dominated by sagebrush scrub. Artemisia nova and Iris missouriensis are often associated with this species. It appears that there is greater germination close to the base of Artemisia shrubs (USDA FS 2007). Thelypodium stenopetalum is associated with vernally wet alkaline clay soils.
|Thelypodium stenopetalum exhibits high variation in population size based on conditions related to climate. This species is more abundant in years with above average rainfall (USDA FS 2007).|
Conservation, Ecology & Research
Alteration of hydrologic regimes
Unauthorized livestock grazing
Continue implementation of the 1998 recovery plan for T. stenopetalum, and the revised Recovery Plan when completed.
Implement actions in the SBNF Meadow Habitat Management Guide.
Continue to monitor fence lines and signing that protects populations and reconstruct in a timely manner as necessary. Work with adjacent landowners to reduce effects of unclassified trail use on NFS lands.
Survey all new occurrences of T. stenopetalum and any occurrences that have not been visited in the past ten years, and record occurrence status, habitat condition, and threats.
Apply the habitat suitability criteria and detection protocol developed for this taxon to surveys at the project level.
Collect a herbarium voucher specimen of T. stenopetalum to document new occurrences or to verify a historical occurrence if the occurrence is not known to have been documented in at least ten years prior.
Stephenson, John R.; Calcarone, Gena M. 1999. Southern California mountains and foothills assessment: habitat and species conservation issues. Albany, CA. Pacific Southwest Research Station, USDA Forest Service. GTR-PSW-172.