Chickweed is actually an herb that started out as a weed in Europe and has been naturalized worldwide. It is so named because it is a favorite food of chickens. Chickweed is an annual, meaning that the plant's life span is over in one year, and the plants for the next year come from seeds, either self-seeded by the plant or sewn in by the gardener.
Chickweed grows from 3 to 8 inches high, and the plants will mat together and grow to about 16 inches long. The leaves, which have smooth edges, are no more than 1 inch long and can be as short as ½ inch and always grow in pairs, directly opposite each other on the stem. The stem itself is not smooth, having a line of hairs covering the entire length. The flowers themselves are petite, measuring just 1/8 inch across. They are white with five petals, giving them a star shape. Directly under the flower petals are five sepals, which look like leaves, and grow as long as the petals.
There are a few different types of chickweed, each one with its own modification on the general features, and all of them are edible. Common chickweed has leaves with stalks, star chickweed has leaves without stalks, and mouse-ear chickweed has coarse hairs.
Common chickweed as well as star chickweed can be eaten raw in salads or cooked just like spinach, for about five minutes. Mouse hair chickweed is a bit tough to eat raw. It has to be cooked. Chickweed is an excellent source of vitamins and minerals including A, D, B complex, C, rutin. iron, calcium, potassium, phosphorus, zinc, manganese, sodium, copper, and silica.
Be careful when picking chickweed. There are poisonous plants that grow the same way, but have different features. Spotted Spurge trails along the ground and has the same leaf characteristics, but has different flowers, and if you break the stem, you will get a milky sap. Matted doorweed, also known as oval-leaf knotweed, also trails along the ground, but the leaves are not opposite one another--they alternate up the stem one by one.