Taxon Report

Oenothera deltoides Torr. & Frém. ssp. julpunensis S.F. Jones

Bay Miwok evening primrose

Print Report

Taxon Summary

Oenothera deltoides ssp. julpunensis, commonly known as Bay Miwok evening primrose, is a annual/perennial herb in the Onagraceae that is found only in California. It occurs within Inland dunes, growing at elevations from 5 to 15 meters. Oenothera deltoides ssp. julpunensis is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Oenothera deltoides Torr. & Frém. ssp. julpunensis S.F. Jones
Common Name:	Bay Miwok evening primrose
Family:	Onagraceae
Element Code:	PDONA0C0B5
USDA Plants Symbol:
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual/perennial herb
Blooming Period: Apr-Jun	Apr-Jun
Elevation:	5-15 (15-50)
General Habitats:	Inland dunes
Microhabitat:	Openings, Sandy
Microhabitat Details:	Endemic to the loose sandy soils of the eastern edge of the Antioch Dunes sand sheet.

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G5T1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:
CRPR Changes:	added to 1B.1 on 2025-04-29

Occurrence Data from the CNDDB


Total Occurrences:	0
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	0

Location


California Endemic: True
California Counties and Islands: Name (Code)

Quads: Name (Quad Code)

Threat List Data from the CNDDB


Threat List Total:	0
EOs with Threat Listed:	Total EOs	% of EOs
	0	0 %

Notes




Threats:
Threatened by development, urbanization, and agriculture.
Taxonomy:
Populations included in ssp. julpunensis were previously assigned to O. deltoides ssp. cognata or thought to be morphological intergrades (or hybrids) between ssp. cognata and ssp. howellii.

Selected References

Proposed addition to CRPR 1B.1, G1 / S1 (2025)

Madroño 71(2): 84-104 (2024)

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 29 October 2025].