Flower:

Flowers are from ¼ to ½ inch across, 5 narrow pale yellow petals with about 20 yellow-tipped stamens surrounding a bright green center. There are 5 yellowish-green sepals behind the flower head; the sepals are about as long as the petals, or longer. Flowers are at the end of stems that arise from a leaf axil. One plant has a few to several flowers.

Leaves and stem:

Leaves are up to 4 inches long and 3 inches wide, lobed or deeply divided into 3 or 5 parts, with long leaf stems that become shorter as leaves ascend the stem. The lobes are coarsely toothed toward the tip end. The main stem and leaf stems are both hairy, and the leaves may also have scattered hairs on the surfaces, and fine hairs along the edges.

Fruit:

The green flower center grows into a round cluster of 1-seeded fruits, each with a hook at the top, and is where the common name originates.