Flower:

Numerous small yellow flowers in an airy panicle at the top of the plant and arising from leaf axils in the upper part of the plant. Clusters hang in a classic shepard's hook prior to blooming. Flowers are light yellow, ¼ to ½ inch across, with 12 to 20 rays (petals) and narrow overlapping bracts forming a tubular receptacle at the flower base, often splotched with dark glands

Leaves and stem:

Leaves are oblong to lance-shaped, to 12 inches long and 3 inches wide, deeply lobed, becoming smaller and often less lobed as they ascend the stem. Leaf edges have tiny teeth and short prickles all around. Leaves have an angular lobe on either side of the leaf base that clasps and usually extends past the stem.

The underside of leaves has a line of prickles along the midrib. Leaf color is blue-green. The main stem is stiff and green or whitish, and may have a few stiff bristles near the base of of the plant.

Fruit:

Fruit is a small brown seed with a tuft of white hair to carry it off in the wind.

Notes:

While there are several species with small yellow dandelion type flowers, Prickly Lettuce is easily distinguished by the prickles on the leaves. A widespread weedy species of disturbed areas, Prickly Lettuce does not often encroach on high grade habitat but with the waste acreage provided by human activity it flourishes.