Stiff Sunflower
Helianthus pauciflorus
Stiff Sunflower (Helianthus pauciflorus) is a native perennial with bristly stems, very rough gray-green leaves, and yellow sunflower heads 5–10 cm (2–4 in) wide with a usually purplish brown center. It blooms July into September on prairies and in open woods across South Dakota, and it is recorded in the Black Hills. Photographed in the Black Hills.
| Family | Asteraceae · Aster |
|---|---|
| Status | Native perennial |
| Blooms | July into September |
| Height | 50–200 cm (20–79 in) |
| Where | Dry prairies, open woods and roadsides; sandy or rocky soil |
| Also called | Prairie Sunflower, Few-leaved Sunflower, Few-flowered Sunflower |
| Synonym | Helianthus rigidus |
Roots, seeds & germination
Root: Rhizomes (underground stems) that form colonies. Primary roots can grow more than 2 m (7 ft) long.
Seed: Achene (dry one-seeded fruit) 5–6 mm long, tipped with 2 bristly scales and smaller ones, with no tuft of hair.
Germination: Seed benefits from cold treatment. Sow in fall, or in spring after about 6 weeks of cold.
How do you identify Stiff Sunflower?
Look for mostly opposite, nearly stalkless, very rough gray-green leaves crowded on the lower half of the plant, long and mostly bare upper stems, a usually purplish brown disk, and short, flat bracts held tight to the head. The disk is sometimes yellow, so check the leaves too.
When does it bloom?
July into September.
Where does it grow?
Dry prairies, open woods and roadsides on sandy or rocky soil, across South Dakota. Black Hills plant lists record the shorter subspecies, subrhomboideus, which grows 50–120 cm (20–47 in) tall.
Other flowers to compare
Sources: SDSU Open PRAIRIE: Helianthus pauciflorus; Minnesota Wildflowers: Stiff Sunflower; Kansas Wildflowers: Stiff sunflower; Flora of North America: Helianthus pauciflorus; Marriott and Hartman 1986, A Survey of the Vegetation of Jewel Cave National Monument; Jewel Cave National Monument Plant Community Composition and Structure Monitoring 2011 Annual Report.