Spiny sowthistle

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Spiny sowthistle leaf

Spiny sowthistle inflorescence

Spiny sowthistle leaf

Spiny sowthistle head

Spiny sowthistle

Spiny sowthistle pappus

Spiny sowthistle

Spiny sowthistle

Spiny sowthistle leaves

Morphology

Stem

Erect, branched in inflorescence.

Leaves

Alternate, stiff, obovate to ovate in outline, pinnately-divided to lobed or nearly entire, glabrous, margins wavy, with prickly spines, base clasping with rounded auricles; lower leaves 1.5 to 6 inches long, .4 to 3 inches wide; upper blades much reduced and less divided.

Inflorescence

Heads, 3-25 in corymb-like cluster, terminal; heads flask-shaped, 1/2 to 1 inch wide; phyllaries lanceolate to linear, 1/3 to 3/5 inch.

Flower

Involcure up to 3/5 inch tall; florets 50-150, all ligulate, fertile; ligule shorter than corolla tube, corolla yellow.

Fruit

Achenes, flattened, about 1/10 inch long, 3-5 ribs on each face; pappus of white, hair-like bristles, 1/4 to 1/3 inch long.

Ecology

Habitat

Moist disturbed sites, waste areas, gardens, roadsides, and cultivated fields.

Distribution

Principally in the east 1/2 of Kansas, but scattered west.

Additional Notes