Slender upright plant, 1 to 3 feet tall. Lowest leaves (below, middle) egg-shaped, shallow-teethed, often with a few lobes at the base. Stem leaves, narrower, pointed, without lobes or stalks. Flowerheads few, in a loose inflorescence. Each head like a small dandelion, with about a dozen yellow ray flowers. Heads open in the morning, tend to close up later in the day. Blooms in mid-summer.

Alien weed of roadsides and waste places. Seems to prefer shadier areas than most weeds. In Wildwood, along the bikeway near the tunnel.

There are a number of plants in the Park with small yellow dandelion flowers. Nipplewort can be distinguished from the others by the leaves; the other species either have leaves much more lobed, or not lobed at all.