Purple Milk Thistle

Reaches an height of 45–70 centimetres (18–28 in). The stem is erect and pubescent, branched at the top. The leaves are green, long and narrow, lanceolate, mottled with white markings, while the underside is whitish and covered with matted woolly hairs (hence the Latin name tomentosa of the species). The margins of the leaves bear strong thorns.
The flowers are hermaphrodite and are pollinated by insects, they are quite large - about 3 centimetres (1.2 in) in diameter-, their color varies from white or pink to lilac-purple. The flower's attachment to the stalk (receptacle) is covered by hairy scales ending with a single grooved thorn. The flowering period extends from July through August and the seeds ripen from August through September. The fruits are achenes with whitish hairy appendages (pappus).