Kansas Wildflowers and Grasses

STIFF SUNFLOWER

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Helianthus pauciflorus Nutt.

[=Helianthus rigidus (Cass. ) Desf.]

Riley County, Kansas

Perennial

Height: 1-7 feet

Family: Asteraceae - Sunflower Family

Flowering Period: July, August, September

Stems:

Erect, simple or sparsely branched above, green or often reddish, rough-hairy.

Leaves:

Variable, widely separated, mostly opposite, stalked below, nearly sessile above, ovate to narrowly oblong-lanceolate, 2 to 12 inches long, 1 to 2.5 inches wide, thick, rough, leathery, gray-green; margins toothed to nearly entire; tips pointed; often folded lengthwise; uppermost leaves bract-like and sometimes alternate.

Inflorescences:

Heads, solitary or several, long-stalked, terminal, 2.5 to 4 inches wide; bracts elliptic to ovate, conspicuously overlapping in several series, pressed tightly against disk, glabrous, margins fringed with stiff hairs; tips pointed to blunt.

Flowers:

Ray florets 10-25, to 1.5 inch long, yellow; disk florets numerous, corollas purplish brown to sometimes yellow with reddish lobes.

Fruits:

Achenes, about 1/4 inch long, mostly glabrous, tipped with 2 conspicuous bristles and smaller secondary scales, enclosing small seed.

Habitat:

Dry or drying prairies, roadsides, and open woods, most abundant in sandy soils.

Distribution:

East 1/2 of Kansas.

Comments:

Stiff sunflower forms colonies by rhizomes and is one of our earliest blooming sunflowers. The primary roots grow more than 7 feet long.

Stiff sunflower