Cirsium Mohavense, Mojave Thistle

Cirsium mohavense produces one stem or several, branching a few times above the middle, and covered with dense, short, greyish-white tomentose hairs. Plants are tall, up to 8 feet, and leaves are correspondingly large, and variable in appearance; they may be simple and lightly spined, or shallowly to deeply pinnately lobed, the lobes linear to triangular or ovate, toothed or entire. The longest spines are over one inch. Both leaf surfaces are also usually tomentose hairy (especially underneath). Leaves grow at the base (not withered at flowering) and all along the stem; the uppermost are simple, well-separated and much reduced in size.

Heads may be single, or (more usually) part of small, open arrays, and are attached by leafy stalks up to 4 inches long. The egg-shaped or hemispherical involucres are ringed by between five and eight rows of green to brownish phyllaries, topped by brown, spreading spines. Below the spine is a narrow ridge, usually whitish. Phyllary margins are loosely tomentose, becoming glabrous when mature. Florets are colored white to lavender or pale pink, and are around one inch long.