Flower:

Flowers are about 1/3 inch across with 5 oblong to egg shaped petals, slightly notched at the tip, white to pinkish lavender with darker lines radiating from the base. The 5 sepals are oval-elliptic with a conspicuous sharp awn at the tip and are hairy on the outer surface; including the awn they are as long as or a little longer than the petals. Flowers are typically borne in pairs, each on a ¾ to 1 inch stalk (pedicel) that splits off at the tip of another ¾ to 1 inch stalk (peduncle) arising from the leaf axils and at the tips of growing branches. New flowers develop continuously through the growing season.

Leaves and stems:

Leaves can be alternate but are mostly opposite on stalks up to 2 inches long. The blade is nearly round in outline, up to 3 inches across, hairy on both surfaces, deeply cleft into 5 (typical) fingerlike lobes that are generally wedge shaped at the base and fan out in their upper half, these lobes further lobed with rounded or blunt tips.

At the base of the leaf stalk is a pair of short, very narrow, sharply pointed, leafy appendages (stipules). Stems are sparsely hairy, spreading to erect with many ascending branches, spreading out to 3 feet across, and are often tinged red. Branches are swollen at the base, leaf stalks slightly so.

Fruit:

Fruit is an erect capsule-like structure about 1 inch long with the persistent sepals around the base. In the center is a slender column divided into five sections, each attached at its base to an oval shaped carpel containing a single seed.

At maturity, the sections split apart from the base along the seams, causing the dried carpels to spring up and eject the seeds away from the mother plant.

Notes:

The native Bicknell's Cranesbill can be distinguished from the non-native Siberian Cranesbill (Geranium sibiricum) by its 2 flowers per cluster and its narrower, more fan-like leaf lobes that have blunt or rounded tips. The leaf lobes of G. sibiricum are more broadly lance elliptic, have sharply pointed tips, and the flowers are nearly always single in the leaf axils on proportionately longer stalks. The native Carolina Cranesbill (G. carolinianum) also has 2 flowers per stalk but they are more densely clustered at the branch tips and are nearly stalkless, creating more of a flat-topped cluster. Distribution range can also be a good indicator. G. bicknellii is predominantly found in northern boreal forests where it responds to disturbances in forest openings, such as lumbering and fire. With only a few exceptions G. carolinianum is almost exclusively found in the western and southern prairie regions, especially in and around rock outcrops.