Taxon Report

Polygonum hickmanii H.R. Hinds & R. Morgan

Scotts Valley polygonum

Print Report

Taxon Summary

Polygonum hickmanii, commonly known as Scotts Valley polygonum, is a annual herb in the Polygonaceae that is found only in California. It occurs within Valley and foothill grassland (mudstone, and sandstone), growing at elevations from 210 to 250 meters. Polygonum hickmanii is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Polygonum hickmanii H.R. Hinds & R. Morgan
Common Name:	Scotts Valley polygonum
Family:	Polygonaceae
Element Code:	PDPGN0L310
USDA Plants Symbol:	POHI14
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: May-Aug	May-Aug
Elevation:	210-250 (690-820)
General Habitats:	Valley and foothill grassland
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	CE
Fed List:	FE
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


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

Location


California Endemic: True
California Counties and Islands: Name (Code)
Santa Cruz (SCR)
Quads: Name (Quad Code)
Felton (3712211), Laurel (3712118)

Threat List Data from the CNDDB


Threat List Total:	8
EOs with Threat Listed:	Total EOs	% of EOs
	2	100 %
Development	2	100%
Non-native plant impacts	2	100%
Other	2	100%
Road/trail construction/maint.	1	50%
Altered flood/tidal/hydrologic regime	1	50%
ORV activity	1	50%
Erosion/runoff	1	50%
Insufficient population/stand size	1	50%

Notes



Known only from Scotts Valley. Fewer than 3500 individuals as of 1998. Threatened by development and non-native plants. Not in TJM (1993). See Novon 5(4):336 (1995) for original description.
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 24 February 2025].