Sunflower family - Asteraceae
Photo from Weeds of the West, revised edition.
Photos from Montana Weed Control Association
Growth Habit: Herbaceous perennial.
Leaves: Lance-shaped, deeply lobed, 2-5 inches long.
Stem: One or more, 20-60 inches long with multiple spreading or ascending light green branches, smooth except for the lowermost 2-3 inches, which are densely covered with stiff, downward-directed hairs.
Flower: Terminate flower-heads individually or in groups of 2-3. Each flower head contains 10-12 bright yellow florets. Flowers are self-fertile.
Seeds: About 3mm long, pale to dark brown and vertically ribbed with scales & tooth-like projections at the tufted end.
Reproduction: Seeds, root cuttings, rosettes from the root crown.
Habitat: Open, waste areas with disturbed soils, along roadsides and in unimproved pastures.
Biological Controls: Skeletonweed gall midge (Cystiphora schmidti), Skeletonweed gall mite (Eriophyes chondrillae), Rush skeletonweed rust (Puccinia chondrillina).
Herbicides: None used in Yellowstone County at this time.
Produced by Wyoming Weed & Pest Council in cooperation with Sandoz Crop Protection Corp.