Carduus is a genus of flowering plants in the family Asteraceae, and the tribe Cardueae, one of two genera considered to be true thistles, the other being Cirsium. Plants of the genus are known commonly as plumeless thistles. They are native to temperate Eurasia and North Africa,

Etymology

The genus name Carduus is from the Latin for "a kind of thistle" or "thistlelike plant". It is also related to the word card, which as a noun means a device (often a stiff-bristled brush) for aligning and cleaning fibers, and as a verb means the action of processing fibers in that way.

Description

These are usually annual or biennial herbs, sometimes perennial. Species often grow 2 meters in height but are known to reach 4 meters. The erect stems are winged and spiny, and usually have woolly hairs. The leaf blades are hairy to hairless and entire or divided into lobes, and they have spine-toothed edges. The flower heads are solitary or borne in inflorescences of up to 20. The head is spherical to cylindrical and covered in several layers of spreading or curving spine-tipped phyllaries. It contains long, tubular disc florets in shades of white, pink, or purple. The fruit is a cypsela tipped with a pappus of barbed bristles or scales. and the United States. Species such as C. acanthoides, C. nutans, C. pycnocephalus, and C. tenuiflorus easily become weedy in disturbed habitat, such as overgrazed pasture. C. nutans is allelopathic, producing compounds that inhibit the growth and development of other plants.

  • Afrocarduus kikuyorum (as Carduus kikuyorum )
  • Afrocarduus leptacanthus (as Carduus leptacanthus )
  • Afrocarduus macracanthus (as Carduus macracanthus )
  • Afrocarduus millefolius (as Carduus millefolius )
  • Afrocarduus nyassanus (as Carduus nyassanus )
  • Afrocarduus ruwenzoriensis (as Carduus ruwenzoriensis )
  • Afrocarduus schimperi (as Carduus schimperi )
  • Afrocarduus silvarum (as Carduus silvarum )

References

  • Carduus. In: Greuter, W. & E. von Raab-Straube. (Eds.) Compositae. Euro+Med Plantbase. 2006.
  • Carduus (a genus of thistles). BioImages: The Virtual Field-Guide (UK). Accessed 2013-02-17.