Page author: David Giblin
Polygonum polygaloides
WTU specimens
Other herbaria
WTU images

Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains.

Habitat: Meadows, vernal pools and rocky ridges, lowlands to mid-elevations in the mountains.

Flowers: June-August

Origin: Native

Conservation Status: Not of concern

Description:
General:

Glabrous, erect or ascending, usually freely branched annual 6-20 cm. tall.

Leaves:

Linear, 10-25 mm. long, 1-2 mm. broad, basally jointed; stipules lacerate, 4-8 mm. long.

Flowers:

Crowded in groups of 1-4 on the branch tips, the branches arising from the axils of obovate, prominent, strongly white-margined bracts that have a green mid-rib; perianth 2.5 mm. long, divided over half the length, the 5 segments oblong-lanceolate, with greenish center and prominent white to pink margins.

Fruits:

Achene with three sharp angles, dark brown, dull, longitudinally striate, 2 mm. long.

Accepted Name:
Polygonum polygaloides Meisn.
Publication: Prodr. 14: 101. 1856.

Synonyms & Misapplications:
(none provided)
Infraspecies:
ssp. confertiflorum – close-flowered knotweed    East of the Cascades, Grant and Kittitas Counties, Washington, to California, east to Montana
ssp. kelloggii – white-margin knotweed    Mostly east of the Cascades, British Columbia to California, east to Montana and Arizona
ssp. polygaloides – Polygala knotweed
Additional Resources:

PNW Herbaria: Specimen records of Polygonum polygaloides in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Polygonum polygaloides checklist entry.

E-Flora BC: Polygonum polygaloides atlas page.

CalPhotos: Polygonum polygaloides photos.

USDA Plants: Polygonum polygaloides information.

31 photographs:
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