1. Achenes pale or tan; longer phyllaries (like the shorter) glabrous within.

C. capillaris

1. Achenes dark purple-brown (rarely paler); longer phyllaries antrorse-strigose within.

2. Plant ± rough-pubescent on leaves and stems; achenes yellow or yellow-brown, ca. 13-25-ribbed, over 4 mm long.

C. biennis

2. Plant smooth or nearly so; achenes dark purple-brown, 10-ribbed, ca. 4 mm long.

C. tectorum