Description: Biennial or winter annual up to 4 feet, 8 feet under ideal conditions. Rosette forms first year, flowers second year. Stem glabrous to wooly, strongly spiny-winged to the flower heads. Leaves 4 to 8 inches long, dark green with a light midrib, deeply divided and sharply-margined. Flowers solitary or in clusters of 2 to 5, purplish to sometimes white or yellowish. Phyllaries narrow, pointed, and sparsely to densley hairy. Seeds golden to brown, striped lengthwise, slightly curved, with a protrusion at one end.
Habitat: Native to Europe. Invades pastures, roadsides, stream valleys, rangelands, and waste areas.
Distribution: Only isolated infestations of plumeless thistle, consisting of only a few square feet, have ever been found in northeastern California.
Flowering Period: May to July.