Seedling
Cotyledons ovate, small, hairless. True leaves variable, oval to lanceolate, tapering into stalks. Few, distinct downward pointing teeth on leaf edges.
Mature plant
Stems are erect, branched, slender, from 3 to 40 inches high at maturity. Leafy stem, smooth to slightly hairy, with a milky sap.
Leaves are alternate, basal leaves much varied, lanceolate, 4 to 6 inches long, usually with irregularly, downward pointing teeth. Leaves narrow into stalk. Upper stem leaves lanceolate to linear, with smooth leaf edges, stalkless, sometimes clasping the stem by small, pointed lobes.
Root structure description
Taproot.
Flowers
Bright yellow, up to 3/4 inch across, dandelion-like heads, usually in groups of 5. Flowers from mid-June to freeze-up. Seeds in heads, dark purple with white hairs on upward ends.