Taxon Report

Helianthus inexpectatus D.J. Keil & Elvin

Newhall sunflower

Print Report

Taxon Summary

Helianthus inexpectatus, commonly known as Newhall sunflower, is a perennial rhizomatous herb in the Asteraceae that is found only in California. It occurs within Marshes and swamps, and Riparian woodland, growing at elevations from 305 to 305 meters. Helianthus inexpectatus is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Helianthus inexpectatus D.J. Keil & Elvin
Common Name:	Newhall sunflower
Family:	Asteraceae
Element Code:	PDAST4N250
USDA Plants Symbol:
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial rhizomatous herb
Blooming Period: Aug-Oct	Aug-Oct
Elevation:	305-305 (1000-1000)
General Habitats:	Marshes and swamps, Riparian woodland
Microhabitat:	Seeps
Microhabitat Details:	freshwater

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:	SB_CalBG/RSABG
CRPR Changes:	added to 1B.1 on 2010-08-16

Occurrence Data from the CNDDB


Total Occurrences:	1
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	1
Poor (D)	0
None (X)	0
Unknown (U)	0

Location


California Endemic: True
California Counties and Islands: Name (Code)
Los Angeles (LAX)
Quads: Name (Quad Code)
Newhall (3411845)

Threat List Data from the CNDDB


Threat List Total:	4
EOs with Threat Listed:	Total EOs	% of EOs
	1	100 %
Altered flood/tidal/hydrologic regime	1	100%
Development	1	100%
Non-native plant impacts	1	100%
Over-collecting/poaching	1	100%

Notes



Known from a single occurrence of fewer than 10 individuals. See Aliso 28:59-62 (2010) for original description.
Threats:
Potentially threatened by development, hydrological alterations, habitat alteration and loss, urban runoff, non-native plants, recreational activities, and foot traffic. Possibly threatened by air pollution and pollination reduction.
Taxonomy:

Selected References

CRPR List Addition on 2010-08-16

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 3 November 2025].