• stem
  • Distinguished from other thistles in the southwest by being small-headed (involucres 1-2 cm), corollas white to pink-purple, bisexual florets, mid-stem leaf bases extending down stem as spiny wings, and heads borne on long peduncles (1-15 cm) in open panicles. (midwestherbaria.org)
  • Extensions from the leaf base down the stem, called wings, can be lacking (Cirsium arvense), conspicuous (Cirsium vulgare), or inconspicuous. (wikipedia.org)