Polygonum sawatchense subsp. sawatchense
Photo: parent species Polygonum sawatchense · no rights reserved · CC0
Family: Polygonaceae · Type: Herb · Native
Polygonum sawatchense subsp. sawatchense is a native California herb in the Polygonaceae family, recognized by rolled leaf margins, smooth edges, and closed flowers.
Polygonum sawatchense is a native annual found in the Klamath Ranges, northern California Coast Ranges, California Ranges, Sierra Nevada, San Joaquin Valley, southwestern California, Great Basin, and desert mountains in dry meadows, pastures, sagebrush, and forest habitats at elevations of 800 to 3,000 meters. Flowering from June to August, this plant produces white or pink-margined green to reddish flowers clustered in open inflorescences 5 to 15 centimeters long. Growing with slender green to brown stems 10 to 50 centimeters tall that are generally branched, it has a delicate, spreading habit. Its narrow leaves are 15 to 45 millimeters long, lance-linear to oblanceolate, with margins rolled under and smooth. The small elliptic or ovate fruits are approximately 3 millimeters long.
Identification and appearance
Key characters: 26 sympatric species; key features are rolled leaf margins, smooth edges, and closed flowers
Habitat and range
Habitat: dry meadows, pastures, sagebrush, forest, sandy, gravelly, rocky substrates
Elevation: 800-3000 m
Outside California: to New Mexico, Canada
Bloom period
Polygonum sawatchense subsp. sawatchense blooms Jun-Aug.
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 sawatchense subsp. sawatchense native to California?
Yes. Polygonum sawatchense subsp. sawatchense is native to California (recorded as native).
When does Polygonum sawatchense subsp. sawatchense bloom?
Polygonum sawatchense subsp. sawatchense blooms Jun-Aug.
What plant family does Polygonum sawatchense subsp. sawatchense belong to?
Polygonum sawatchense subsp. sawatchense is in the Polygonaceae family, genus Polygonum.
What habitat does Polygonum sawatchense subsp. sawatchense grow in?
Polygonum sawatchense subsp. sawatchense grows in dry meadows, pastures, sagebrush, forest, sandy, gravelly, rocky substrates.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
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.