Spinach, an annual herb used as a vegetable. Spinach is native to southwestern Asia and has been grown in the United States since the early 19th century. The leaves of the plant are eaten cooked or used raw in salads. They are rich in vitamins A and C and contain iron and calcium.
Spinach has large, deep-green, arrow-head-shaped leaves. Some varieties of spinach are wrinkly-leaved while others are smooth-leaved. The leaves grow close to the ground, branching off in the shape of a rosette from a short central stem. As the plant matures, the stem sends up a branching flower stalk, two to three feet (60 to 90 cm) in height. Clusters of small flowers are borne along the stalk and these later develop into small capsules of seeds. Spinach is a cool-weather plant that requires much moisture. It grows quickly and is ready for harvest 6 to 10 weeks after planting. Cultivated spinach is picked before the plant blooms and bears fruit.
Spinach is Spinacia oleracea of the goosefoot family, Chenopodiaceae.