Spinach is an edible flowering plant in the family of Amaranthaceae. It is native to central and southwestern Asia . It is
an annual plant (rarely biennial), which grows to a height of up to 30 cm. Spinach may survive over winter in temperate regions. The leaves are alternate, simple, ovate to triangular-based, very variable in size from about 2–30 cm long and 1–15 cm broad, with larger leaves at the base of the plant and small leaves higher on the flowering stem. The flowers are inconspicuous, yellow-green, 3–4 mm diameter, maturing into a small, hard, dry, lumpy fruit cluster 5–10 mm across containing several seeds.
Common spinach, Spinacia oleracea, was long considered to be in the Chenopodiaceae family, but in 2003, the Chenopodiaceae family was combined with the Amaranthaceae family under the family name 'Amaranthaceae' in the order Caryophyllales. Within the Amaranthaceae family, Amaranthoideae and Chenopodioideae are now subfamilies, for the amaranths and the chenopods, respectively.
Types of spinach[]
A distinction can be made between older varieties of spinach and more modern ones. Older varieties tend to bolt too early in warm conditions. Newer varieties tend to grow more rapidly, but have less of an inclination to run up to seed. The older varieties have narrower leaves and tend to have a stronger and more bitter taste. Most newer varieties have broader leaves and round seeds.
Savoy[]
Savoy Spinach has dark green, crinkly and curly leaves. It is the type sold in fresh bunches in most supermarkets in the United States. One heirloom variety of savoy is 'Bloomsdale', which is somewhat resistant to bolting. Other common heirloom varieties are 'Merlo Nero' (a mild variety from Italy) and 'Viroflay' (a very large spinach with great yields).
Flat- or smooth-leaf spinach[]
Flat- or smoot- leaf spinach has broad, smooth leaves that are easier to clean than Savoy. This type is often grown for canned and frozen spinach, as well as soups, baby foods, and processed foods.
Semi-savoy[]
Semi-savoy Spinach is a hybrid variety with slightly crinkled leaves. It has the same texture as Savoy, but it is not as difficult to clean. It is grown for both fresh market and processing. 'Five Star', a widely grown variety, has good resistance to running up to seed.