The tomato (Lycopersicon lycopersicum, syn. Solanum lycopersicum) is an herbaceous, usually sprawling plant in the Solanaceae or nightshade family, as are its close cousins tobacco, chili peppers, potato, and eggplant. The tomato is native to Central, South, and southern North America from Mexico to Argentina. Evidence supports the theory that the first domesticated tomato was a little yellow fruit, ancestor of L. cerasiforme, grown by the Aztecs in Mexico who called it ‘xitomatl’ (pronounced zee-toe-má-tel), meaning plump thing with a navel. It is a perennial, often grown outdoors in temperate climates as an annual, typically reaching to 1-3m (3 to 10 ft) in height, with a weak, woody stem that often vines over other plants. The leaves are 10–25 cm long, odd pinnate, with 5–9 leaflets on petioles, each leaflet up to 8cm long, with a serrated margin; both the stem and leaves are densely glandular-hairy. The flowers are 1–2cm across, yellow, with five pointed lobes on the corolla; they are borne in a cyme of 3–12 together. The word tomato derives from a word in the Nahuatl language, tomatl. The specific name, lycopersicum, means "wolf-peach" (compare the related species Solanum lycocarpum, whose scientific name means "wolf-fruit", common name "wolf-apple"), as they are a major food of wild canids in South America.
There are a great many tomato varieties grown for various purposes. Heirloom strains are becoming increasingly popular, particularly among home gardeners and organic producers, since they tend to produce more interesting and flavorful crops at the possible cost of some disease resistance. Hybrid plants remain common, since they tend to be heavier producers and sometimes combine unusual characteristics of heirloom tomatoes with the ruggedness of conventional commercial tomatoes.
Tomato varieties are roughly divided into several categories, based mostly on shape and size. "Slicing" or "globe" tomatoes are the usual tomatoes of commerce; beefsteak are large tomatoes often used for sandwiches and similar applications - their kidney-bean shape makes commercial use impractical along with a thinner skin and being not bred for a long shelf life; globe tomatoes are of the category of canners used for a wide variety of processing and fresh eating; oxheart tomatoes can range in size up to beefsteaks, and are shaped like large strawberries; plum tomatoes, or paste tomatoes which does include pear tomatoes, are bred with a higher solid content for use in tomato sauce and paste and are usually oblong; pear tomatoes are obviously pear shaped and based upon the San Marzano types for a richer gourmet paste; cherry tomatoes are small and round, often sweet tomatoes generally eaten whole in salads; and grape tomatoes which are a more recent introduction are smaller and oblong used in salads.
Tomatoes are also commonly classified as determinate or indeterminate. Determinate, or bush, types bear a full crop all at once and top off at a specific height; they are often good choices for container growing. Determinate types are preferred by commercial growers who wish to harvest a whole field at one time, or home growers interested in canning. Indeterminate varieties develop into vines that never top off and continue producing until killed by frost. They are preferred by home growers and local-market farmers who want ripe fruit throughout the season. As an intermediate form, there are plants sometimes known as "vigorous determinate" or "semi-determinate"; these top off like determinates but produce a second crop after the initial crop. The majority of heirloom tomatoes are indeterminate, although some determinate heirlooms exist. |