Taxon Report

Nemacaulis denudata Nutt. var. denudata

coast woolly-heads

Print Report


Taxon Summary

Nemacaulis denudata var. denudata, commonly known as coast woolly-heads, is a annual herb in the Polygonaceae that is found in California and elsewhere. It occurs within Coastal dunes, growing at elevations from 0 to 100 meters. Nemacaulis denudata var. denudata is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

  Classification
Scientific Name:
 Nemacaulis denudata Nutt. var. denudata
Common Name:
 coast woolly-heads
Family: Polygonaceae
Element Code: PDPGN0G011
USDA Plants Symbol: NEDED
Synonyms/Other Names:

Ecology and Life History
Lifeform: annual herb
Blooming Period: Apr-Sep Apr-Sep
Elevation: 0-100 (0-330)
General Habitats: Coastal dunes
Microhabitat:
Microhabitat Details:

Conservation Status
CA Rare Plant Rank: 1B.2
Global Rank: G3G4T2
State Rank:
 S2
State List: None
Fed List: None
Other Status: SB_CalBG/RSABG; SB_CRES
CRPR Changes:

Occurrence Data from the CNDDB
Total Occurrences: 42
Element Occurrence Ranks:
   Excellent (A) 0
   Good (B) 5
   Fair (C) 5
   Poor (D) 1
   None (X) 0
   Unknown (U) 31

Location
California Endemic:  False
California Counties and Islands: Name (Code)
Los Angeles (LAX), Orange (ORA), San Diego (SDG), San Luis Obispo (SLO)
Quads: Name (Quad Code)
Del Mar (3211782), Encinitas (3311713), Imperial Beach (3211751), La Jolla (3211772), Las Pulgas Canyon (3311734), Long Beach (3311872)*, Los Alamitos (3311871), Morro Bay South (3512037), National City (3211761), Newport Beach (3311768), Oceano (3512015), Oceanside (3311724), Point Loma (3211762), San Luis Rey (3311723), San Pedro (3311863), Santa Catalina East (3311833)*, Seal Beach (3311861)

Threat List Data from the CNDDB

Threat List Total: 9
EOs with Threat Listed: Total EOs % of EOs
12 29 %
Non-native plant impacts 9 21%
Foot traffic/trampling 8 19%
Other 3 7%
Erosion/runoff 2 4%
Biocides 1 2%
Disking 1 2%
Recreational use (non-ORV) 1 2%
Vandalism/dumping/litter 1 2%
ORV activity 1 2%

Notes
Much reduced by coastal development. Intergrades with var. gracilis at some localities. Threatened by foot traffic, trampling, and non-native plants. See Madroño 27(2):101-109 (1980) and Phytologia 66(4):390-91 (1989) for taxonomic treatments.
Threats:
Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 25 October 2025].