Taxon Report

Pedicularis rigginsiae D.J. Keil

Arroyo de la Cruz lousewort

Print Report

Taxon Summary

Pedicularis rigginsiae, commonly known as Arroyo de la Cruz lousewort, is a perennial herb (hemiparasitic) in the Orobanchaceae that is found only in California. It occurs within Chaparral, growing at elevations from 100 to 155 meters. Pedicularis rigginsiae is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Pedicularis rigginsiae D.J. Keil
Common Name:	Arroyo de la Cruz lousewort
Family:	Orobanchaceae
Element Code:	PDSCR1K170
USDA Plants Symbol:
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb (hemiparasitic)
Blooming Period: Jan-May	Jan-May
Elevation:	100-155 (330-510)
General Habitats:	Chaparral
Microhabitat:	Clay
Microhabitat Details:	Ultramafic (highly weathered)

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:
CRPR Changes:	added to 1B.1 on 2021-02-17

Occurrence Data from the CNDDB


Total Occurrences:	3
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	1
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	2

Location


California Endemic: True
California Counties and Islands: Name (Code)
San Luis Obispo (SLO)
Quads: Name (Quad Code)
Piedras Blancas (3512163), San Simeon (3512162)

Threat List Data from the CNDDB


Threat List Total:	1
EOs with Threat Listed:	Total EOs	% of EOs
	1	33 %
Wood cutting or brush clearing	1	33%

Notes




Threats:
Threatened by low population numbers. Potentially threatened by ranching activities and development.
Taxonomy:
Previously included in Pedicularis dudleyi.

Selected References

Proposed Addition to California Rare Plant Rank 1B.1, G1 / S1 (2021)

Phytoneuron 2019-2: 1–8 (2019)

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 7 December 2025].