Bull thistle

Images

Click on image to view full size

Bull thistle leaf

Bull thistle

Bull thistle leaves

Bull thistle inflorescence

Bull thistle heads and achene bristles

Bull thistle inflorescence

Bull thistle habit

Bull thistle

Bull thistle inflorescence bracts and florets

Bull thistle

Bull thistle

Morphology

Stem

Erect, stout, much branched, leafy, green or brownish, furrowed, spreading coarse-hairy or covered with cob-web like hairs; upper portion conspicuously spiny-winged.

Leaves

Alternate, simple, green, wavy or crinkled, deeply cleft in pinnate fashion; upper surface short coarse-hairy with yellowish prickles; lower surface pale green or grayish woolly along the veins; young leaves elliptic to obovate, initially unlobed but soon shallowly to pinnately lobed; margins with yellowish spines 1/25 to 1/5 inch long; rosette leaves oblanceolate to narrowly elliptic, 5 to 20 inches long, 1.2 to 6 inches wide, deeply pinnately lobed; lobes in 4-6 pairs, frequently 2-cleft; segments lanceolate to triangular; tips sharp-pointed or tapering to long points, tipped with stout spine to 2/5 inch long, yellow; stem leaves similar but progressively smaller; lobes often linear-lanceolate.

Inflorescence

Heads, several, terminal and solitary on branches, often appearing clustered, urn-shaped, .8 to 1.6 inches tall, .8 to 2 inches in diameter.

Flower

Bracts in 5-8 rows, narrowly lanceolate, .25 to 1.2 inches long,, less than 1/12 inch wide, progressively longer and narrower from outer to inner, cobwebby, spine-tipped, lacking conspicuous ridge on back; ray florets absent; disk florets numerous, 1 to 1.4 inches long, dark purple or rose to pinkish-purple.

Fruit

Achene, oblong, 1/8 to 1/6 inch long, flattened, white or pale yellow with dark brown streaks, tipped with white or brownish feather-like bristles, enclosing small seed.

Ecology

Habitat

Waste areas, pastures, roadsides, old fields, gardens.

Distribution

Throughout Kansas.

Reproduction

By seed.

Practical Information

Uses

Native Americans drank a warm tea of the roots to aid digestion and used the steam to treat muscle stiffness and rheumatism. A tea of the leaves was taken for neuralgia. The roots were also used to treat stomach cramps and were eaten as a food source. The fresh flowers were chewed to cover up the taste of medicines and the achene bristles were used as the tail for blow darts.

Additional Notes