Rubberweed (2)

Rubberweeds, also commonly called Bitterweeds, usually have 8 petals with three-toothed tips which droop when the plant ages. The yellow disk flowers form a dome. Leaves are divided into narrow segments. See also Old-Man-of-the-Mountain.

Hymenoxys richardsonii

Pingue Rubberweed
Hymenoxys richardsonii var. richardsonii

Family: Sunflower (Asteraceae)
AKA: Richardson's Bitterweed
Photo taken on: August 23, 2004
Location: Almont Triangle, GV, CO
Life Zones: Foothills to montane
Habitat: Dry rocky meadows and slopes

Grows to 18" with up to 10 woody stems and 30 flower heads per plant. Flowers are ¾" across.

Flora of North America reference.

Hymenoxys richardsonii

Colorado Rubberweed
Hymenoxys richardsonii var. floribunda

Family: Sunflower (Asteraceae)
AKA:
Photo taken on: August 26, 2014
Location: SR 285, NM/CO State line
Life Zones: Plains and foothills
Habitat: Roadsides, dry, open areas

Very similar in appearance to Pingue Rubberweed but on a much smaller scale. Grows to less than 10" high with up to 20 stems and 200 flower heads.  The flowers are less than ½" across.

Flora of North America reference.

Yellow Round Clusters