Polygonum hickmanii
Scotts valley polygonum, Scotts Valley Polygonum
Family: Polygonaceae · Type: Herb · Native
Conservation status: CNPS 1B.1 · Endangered
Polygonum hickmanii (Scotts valley polygonum) is a native California herb in the Polygonaceae family, recognized by extremely restricted range and compact cushion habit.
Scotts valley polygonum is a rare (CNPS 1B.1) California native annual found in northern San Francisco Bay region at the north end of Scotts Valley, Santa Cruz County, in open, seasonally dry grassland at elevations of 200 to 300 meters. Flowering from May to October, this plant produces white to pink-margined flowers with delicate orange-pink anthers, clustered in compact axillary clusters. Growing with extremely short erect stems 2 to 5 centimeters tall, it forms a distinctive cushion-like compact habit. Its linear leaves are narrow, just 1 to 1.5 millimeters wide, with margins rolled under and tapering to an acuminate tip. The tiny olive-brown fruit is smooth and shiny, measuring 2 to 2.5 millimeters long.
Identification and appearance
Key characters: 14 sympatric species; extremely restricted range and compact cushion habit
Habitat and range
Habitat: Open, seasonally dry grassland
Elevation: 200-300 m
California counties: Santa Cruz
Bloom period
Polygonum hickmanii blooms May-Oct.
Conservation status
CNPS 1B.1 · Endangered
How to tell it apart
vs Euphorbia: Polygonum has swollen stem joints with papery sheaths; Euphorbia has milky sap when broken.; vs Persicaria: Hold node sheaths to light—Polygonum's are translucent and split; Persicaria's are opaque and intact.; vs Eriogonum: Polygonum has papery sheaths at nodes; Eriogonum has flowers in cup-like involucres.; vs Acmispon: Polygonum has swollen stem nodes; Acmispon has compound leaves with 3-5 leaflets.; vs Atriplex: Polygonum has papery stem sheaths; Atriplex has mealy or scurfy coating on leaves.
Frequently asked questions
Is Polygonum hickmanii native to California?
Yes. Polygonum hickmanii is native to California (recorded as native).
When does Polygonum hickmanii bloom?
Polygonum hickmanii blooms May-Oct.
Where in California does Polygonum hickmanii grow?
Polygonum hickmanii occurs in Santa Cruz, at elevations of 200-300 m.
What plant family does Polygonum hickmanii belong to?
Polygonum hickmanii is in the Polygonaceae family, genus Polygonum.
Is Polygonum hickmanii rare or endangered?
Polygonum hickmanii carries California Rare Plant Rank 1B.1, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.