Chickweed, in botany, a genus of the pentandra trigynia clasps: The calyx is divided into five parts; the flowers consist of five petals divided in the middle; and the capsule has three valves. There are three species of the alsine, viz., the media, or common chickweed, a native of Britain; the mucronata, a native of Switzerland; and the segetalis, a native of France.

The affine media has sometimes been recommended in medical cases.