Taxon Report

Oenothera deltoides Torr. & Frem. ssp. howellii (Munz) W. Klein

Antioch Dunes evening-primrose

Print Report



  Classification

Scientific Name:
Oenothera deltoides Torr. & Frem. ssp. howellii (Munz) W. Klein
Common Name:
Antioch Dunes evening-primrose
Family: Onagraceae
Element Code: PDONA0C0B4
USDA Plants Symbol: OEDEH
Synonyms/Other Names:

Occurrence Data from the CNDDB

Total Occurrences: 10
Element Occurrence Ranks:
   Excellent (A) 0
   Good (B) 0
   Fair (C) 4
   Poor (D) 1
   None (X) 1
   Unknown (U) 4
California Endemic:  True
California Counties and Islands: Name (Code)
Contra Costa (CCA), Sacramento (SAC)
Quads: Name (Quad Code)
Antioch North (3812117), Brentwood (3712186), Clayton (3712188), Honker Bay (3812118), Jersey Island (3812116), Walnut Creek (3712281)

Threat List Data from the CNDDB

Threat List Total: 7
EOs with Threat Listed: Total EOs % of EOs
6 60 %
Non-native plant impacts 4 40%
Other 2 20%
Development 2 20%
Mining 2 20%
Biocides 1 10%
Foot traffic/trampling 1 10%
Recreational use (non-ORV) 1 10%

Notes

Occurrences from SAC Co. (480C) and CCA Co. (481C) are introduced. Seriously threatened by mining, agriculture, industrial development, and non-native plants. Recovery work in progress. Protected in part at Antioch Dunes NWR (USFWS). See Aliso 2:81 (1949) for original description, Four Seasons 3(1):2-4 (1969) for threat information, and Biological Conservation 65:257-278 (1993) for population biology.
Threats:
Taxonomy:

Selected References

Recovery Plan for Oenothera deltoides ssp. howellii (Antioch Dunes evening-primrose) (1984)
Recovery Plan Amendment for Oenothera deltoides ssp. howellii (Antioch Dunes evening-primrose) (1984)
Critical habitat for Oenothera deltoides ssp. howellii
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 5 January 2025].