Taxon Report

Polyctenium williamsiae Rollins

Williams' combleaf

Print Report

Classification


Scientific Name:	Polyctenium williamsiae Rollins
Common Name:	Williams' combleaf
Family:	Brassicaceae
Element Code:	PDBRA23030
USDA Plants Symbol:	POWI
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Mar-Jul	Mar-Jul
Elevation:	1347-2700 (4420-8860)
General Habitats:	Great Basin scrub, Marshes and swamps, Pinyon and juniper woodland, Playas, Vernal pools
Microhabitat:	Lake Margins, Sandy, Volcanic
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2Q
State Rank:	S1
State List:	None
Fed List:	None
Other Status:	BLM_S; USFS_S
CRPR Changes:	changed from 1B.2 to 1B.2 on 2012-02-08

Occurrence Data from the CNDDB


Total Occurrences:	6
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	3
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	3

Location


California Endemic: False
California Counties and Islands: Name (Code)
Lassen (LAS), Mono (MNO)
Quads: Name (Quad Code)
Anderson Mtn. (4012085), Aurora (3811838), Cedar Hill (3811827), Dome Hill (3811931), Shaffer Mtn. (4012043), West of Huntoon Spring (3811816)

Threat List Data from the CNDDB


Threat List Total:	6
EOs with Threat Listed:	Total EOs	% of EOs
	5	83 %
Grazing	4	66%
Foot traffic/trampling	2	33%
Agriculture	1	16%
Mining	1	16%
Road/trail construction/maint.	1	16%
Surface water diversion	1	16%

Notes



Threatened by grazing and trampling. Possibly threatened by recreational activities. State-listed as Critically Endangered in NV. A synonym of P. fremontii in TJM 2. See Journal of the Arnold Arboretum 64:508 (1983) for original description, and Intermountain Flora 2B:416-419 (2005) for taxonomic treatment.
Threats:

Taxonomy:

Selected References

CRPR List Deletion on 2012-02-08

Citation California Native Plant Society, Rare Plant Program. 2024. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 25 December 2024].