Page authors: Don Knoke, David Giblin
Grindelia squarrosa
curlycup gumweed, serrate resinweed

Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across southern Canada and most of the United States to the Atlantic Coast.

Habitat: Dry, open, often sandy places, at low to middle elevations, often where disturbed.

Flowers: June-September

Origin: Introduced from the Great Plains and possibly Rocky Mountains area

Conservation Status: Not of concern


Glabrous biennial or short-lived perennial, 1-10 dm. tall.


Leaves usually with fine to coarse, thickened teeth; the lower leaves oblanceolate, up to 15 cm. long and 3 cm. wide, the middle and upper leaves somewhat reduced and clasping the stem.


Heads several, the disk 1-2 cm. wide; rays 25-40, pistillate and fertile, yellow, 7-15 mm. long; involucre strongly resinous, imbricate, the green tips of the bracts reflexed; pappus of 2 or more deciduous awns.


Achenes truncate at the apex.

Accepted Name:
Grindelia squarrosa (Pursh) Dunal
Publication: Mém. Mus. Hist. Nat. 5: 50. 1819.

Synonyms & Misapplications:
Grindelia squarrosa (Pursh) Dunal var. serrulata (Rydb.) Steyerm. [HC]
Grindelia squarrosa (Pursh) Dunal var. squarrosa [HC]
Additional Resources:

PNW Herbaria: Specimen records of Grindelia squarrosa in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Grindelia squarrosa checklist entry.

E-Flora BC: Grindelia squarrosa atlas page.

CalPhotos: Grindelia squarrosa photos.

USDA Plants: Grindelia squarrosa information.

38 photographs:
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