Flower:

1 to a few flowers are at the end of branching stems at the top of the plant. Individual flowers are about ½ inch across with 5 yellow round to oval petals that may have a dull point or a small notch at the tip. There are numerous yellow-tipped stamens, that turn reddish brown with age, surrounding the greenish center. The 5 sharply pointed green sepals under the flower eventually bend back away from the flower.

Leaves and stem:

There are a few to several long stemmed compound basal leaves with a large leaflet at the end and 2 to 6 pairs of small leaflets along the stem. Leaflets are somewhat variable in shape, from wedge to egg-shaped and may lobed in 2 or 3 parts with the lobes broadest at the tip end.

The compound stem leaves are alternately attached; the end leaflet may be divided into 2 or 3 pointed lobes. The end leaflet is to 4½ inches long and 3½ inches wide. There are 2 leaf-like appendages (stipules) attached to the main stem at the leaf joint. Stem leaves near the base of the plant have 1 or more additional pairs of smaller leaflets. All leaves are coarsely toothed and bristly hairy. The main stem is covered in stiff hairs.

Fruit:

Fruit is a dry oval seed; the seed head is covered in hooks

Notes:

The flowers, stem leaves and stipules of Yellow Avens are very much the same as Large-leaf Avens (G. macrophyllum). The easiest way to tell them apart is by the basal leaves; the latter has a big rounded end leaflet.