Grindelia squarrosa (Gumweed) - photos and description

Grindelia squarrosa
15 cm ruler for scale

Grindelia squarrosa

Grindelia squarrosa

Grindelia squarrosa

Grindelia squarrosa

Grindelia squarrosa

Grindelia squarrosa
Lower stem leaf in above photo, lower leaves have petioles.

Grindelia squarrosa
Upper leaf in above photo.

General: Plants erect, often many-branched. The bracts of the flower heads are very sticky - giving rise to its common name - Gumweed. Stems and leaves glabrous.

Flowers: Flowers numerous in flat topped clusters, yellow, measured to 3 cm diameter. Involucre bracts imbricate in several series, very sticky. Flowers late July through September.

Leaves: Leaves are alternate, sparsely toothed, upper leaves sessile and clasping, oblong, measured at 3 cm long, and 1 cm wide. Lower leaves petiolate, spatulate, measured at 7 cm long, 1 cm wide.

Height: Height listed in Budd's Flora to 60 cm, I measured plants to 53 cm tall.

Habitat: Dry grassland and prairie roadsides.

Abundance: Very common.

Origin: Native.

When and where photographed: The above photos were taken August 26th roadside in the Qu'Appelle Valley, 30 km north of Regina, SK, and September 2nd in a highway ditch, about 100 km north of our home in Regina, SK.