Helianthus californicus

Rarity

CNPS-EB: C

16 current natural populations

Criteria:

Limited/Threatened Habitat
Small Populations

Observations

CNPS-EB Database ⓘ
Calflora (group) ⓘ
Calflora (public)
iNaturalist
- Genus Helianthus
- Helianthus californicus
CCH2

Key

Ecology

Flowers July - October

Habitats:

Brackish Marsh
Freshwater Marsh
Riparian
Rock, Tallus, Scree

All Helianthus

H. californicus
H. gracilentus (B)

References

Populations

Key

Location	Pop ID	Last Recorded	Notes
Corral Hollow Area	4	2003-09-08
Del Valle Regional Park	18	2020-07-18
Lawrence Livermore Lab, Site 300, Corral Hollow	5	2021-12-31
Los Vaqueros Watershed	33	2025-10-11
Mines Road/Arryo Mocho	21	2003-09-12
Mt. Diablo State Park - East side	7	2003-09-11
Mt. Diablo State Park - North side	8	2025-09-06
Mt. Diablo State Park - North side	9	2023-07-16
Mt. Diablo State Park - North side	11	2003-09-11
Mt. Diablo State Park - North side	12	2021-07-08
Mt. Diablo State Park - South side	14	2008-10-13
Mt. Diablo State Park - West side	16	2024-09-29
Pacheco Slough	23	2025-08-10
Pacheco Slough	32	2004-09-02
Pittsburg Shore	26	2022-07-21
San Francisco Water District land, Sunol	27	2009-12-31
Browns Island	1	1991-08-18	Historic
Cedar Mountain	2	1993-06-27	Historic
Chabot Rgnl Park	3	1997-07-11	Historic
Diablo Foothills Rgnl Park	6	1997-12-31	Historic
Leona Heights Rgnl Park, or nearby	19	1866-09-30	Historic
Los Mochos Boy Scout Camp, Mines Rd	20	1996-07-12	Historic
Martinez shoreline - out of park or specific site unknown	22	1999-12-31	Historic
Mt. Diablo State Park - North side	10	1994-12-31	Historic
Mt. Diablo State Park - South side	13	1998-07-21	Historic
Mt. Diablo State Park - West side	15	1991-03-31	Historic
Mt. Diablo State Park - West side	17	1994-12-31	Historic
Peyton Marsh, Martinez	24	1998-12-31	Historic
Pt. Edith	25	1996-10-17	Historic
Pt. Pinole Rgnl Park	31	1979-10-07	Historic
Sunol Rgnl Wilderness	28	1991-05-06	Historic
Tilden Rgnl Park - other or unknown sites	29	1994-07-11	Historic
Tilden Rgnl Park - other or unknown sites	30	1994-07-11	Historic

The list of populations shows the distinct populations identified by the CNPS-EB Rare and Unusual Plants Committee. The locations in this list are very general. More specific location details can be obtained from the links in the Observations section (for some of these links, a login is required).

Font

Populations in bold type have precise coordinates available for field volunteers and researchers.

Populations in normal type are only known from a description of the location; no precise coordinates are available.

Background

Populations with a white background have been observed in the last 25 years.

Populations with a blue background have not been observed for at least 25 years.

Populations with an orange background have an uncertain location or identification, or are planted.

Columns

Pop ID is a label that identifies the population. Many locations have more than one population of a species, and the population ID is used to distinguish them.