This genus comprises annual or biennial flowering plants commonly referred to as 'plumeless thistles.' Originating from Eurasia and Africa, several species are considered problematic for agricultural and horticultural settings. The plants feature upright stems that are hairy and spiny, along with lobed leaves that have toothed edges. Flowering heads are rounded and bristle-covered, appearing in white, pink, or purple hues.

Carduus

Carduus acanthoides L.

Carduus acicularis

Carduus anglicus

Carduus arvensis

Carduus aurosicus

Carduus baeocephalus Webb.

Carduus carduelis

Carduus carlinoides

Carduus crispus, commonly known as the welted thistle, is a biennial plant that can grow to a height of 1.5 meters. It features lobed leaves and stems that are both spiny and winged, with a fuzzy texture. The upper portions of the stems support clusters of purple flowers, which bloom from June to August and are surrounded by hairy bracts.

Carduus crispus

Carduus defloratus

Carduus defloratus subsp. argemone

Carduus defloratus subsp. crassifolius

Carduus defloratus subsp. defloratus

Carduus edulis

Carduus eriophorus L.

Carduus euosmus W.W. Sm

Carduus keniensis

Carduus macrocephalus

Carduus myriacanthus

Carduus nutans is a biennial plant characterized by its erect growth habit and fuzzy stems. Its leaves are spiny, green, and divided, contributing to its distinctive appearance. From June to August, the plant produces sizable, purple, pendulous flower heads measuring approximately 3 to 5 centimeters in diameter. These flowers lack ray florets and are encircled by a ring of pink bracts.