Seedling
Cotyledons oblong to broadly oval. True leaves irregularly lobed, with spiny edges and somewhat hairy underneath.
Mature plant
Stems erect, branching only at the top, growing to 5 feet tall. Stems usually hairless when young with hairiness increasing with maturity. Stems very leafy.
Leaves alternate, roughly lanceolate, but irregularly and deeply lobed. Lobes may have spiny teeth and be crinkled along the edges. Leaves 2 to 6 inches long, smooth above and usually hairy below. Leaves stiff and usually stalkless, clasping the stems. Basal leaves may have stalks.
Root structure description
Creeping roots, horizontal, deep.
Flowers
Flowers lavender, rose-purple or less commonly white, with compact heads about 1 inch or less in diameter. Male and female flowers usually in separate heads and borne on different plants. Male heads are globe-shaped, while female heads are flask-shaped. Seeds are small and brown with a white, feathery pappus. Flowers throughout the summer.
