Yellow-spine thistle

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Yellow-spine thistle leaf

Yellow-spine thistle phyllaries

Yellow-spine thistle decurrent leaf base

Yellow-spine thistle

Yellow-spine thistle

Yellow-spine thistle

Yellow-spine thistle

Morphology

Stem

Erect or ascending, simple or branched distally, densely white-tomentose.

Leaves

Basal and cauline; blades oblong to narrowly elliptic, 4 to 12 inches long, .8 to 3.2 inches wide, base tapered to winged petiole, strongly decurrent for .4 to .8 inch with spiny wings, margins strongly undulate, coarsely dentate to shallowly or deeply pinnately lobed, lobes triangular, primary spines .16 to .8 inch, abaxial surface densely white-tomentose, adaxial surface thinly gray-tomentose, without appressed prickles.

Inflorescence

Heads discoid, 1-few in corymb-like arrays. Involucres ovoid to campanulate or hemispheric, .9 to 1.6 inch long, .8 to 1.4 inch wide. Phyllaries many, overlapping in 5-7 series, outer phyllaries ovate, abaxial faces with narrow glutinous ridge, apex bearing spreading spine .16 to .5 inch, inner phyllaries narrowly lanceolate.

Flower

Florets 25-200, bisexual, fertile; corollas purple to lavender or whitish, 1.2 to 1.5 inch.

Fruit

Achenes, brown, .24 to .28, glabrous, apical collar brown; seed 1; pappus white or tawny, .8 to 1.4 inch.

Ecology

Habitat

Mixed-grass, shortgrass, and sandsage prairies, pastures

Distribution

West 2/3 of Kansas

Practical Information

Uses

The Kiowa used flowers of this species, boiled in water, in a preparation to treat burns and skin sores and the Zuni took an infusion of the entire plant to treat syphilis.

Additional Notes