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Brassica - Cabbage BRASSICA (brass'i-ka). A botanically confusing genus, but horticulturally important and temperate Old World annual or biennial herbs - leaf or flowering plants - of the family Brassicaceae (Cruciferae), containing not only the mustard, but all the vegetables of the cabbage tribe, as well as rape, turnip, and others (see below). Some, also, are pernicious weeds {see Wild Mustard). The members of the genus may be collectively known either as cabbages, or as mustards. They have mostly smooth, often bluish-green, water-shedding leaves which may be cut, lobed, or toothed. Flowers (lacking in most of the vegetables as harvested) yellow or white, with 4 petals, and in terminal clusters (racemes). Fruit a long pod (silique), usually stalked. (Brassica is the classical name for cabbage.) The exact name of most of the species is lost in antiquity. Many of the vegetables have been cult, over 2000 years. The cabbage head was bred into the species from the leafy wild plant, found native in the Mediterranean region around 100 AD. The English name derives from the French caboche (head). This genus is remarkable for containing more important agricultural and horticultural crops than any other genus. Varieties include Red cabbage and Savoy cabbage. It also includes a number of weeds, both wild taxa and escapes from cultivation. It includes over 30 wild species and hybrids, and numerous additional cultivars and hybrids of cultivated origin. Chinese cabbage, while resembling cabbage, is an independent development from a different Brassica species. Most plants of this genus are annuals or biennials, but some are small shrubs. The genus is native in the wild in western Europe, the Mediterranean and temperate regions of Asia. Through the centuries, plant breeders and explorers have developed unique and flavorful vegetables that have been transported and transplanted around the globe.In addition to the cultivated species, which are grown worldwide, many of the wild species grow as weeds, especially in North America, South America, and Australia. Almost all parts of some species or other have been developed for food, including the root (swedes, turnips), stems (kohlrabi), leaves (cabbage, brussels sprouts), flowers (cauliflower, broccoli), and seeds (many, including mustard seed, oilseed rape). Some forms with white or purple foliage or flowerheads, are also sometimes grown for ornament. There is some disagreement among botanists on the classification and status of Brassica species and subspecies. The following is an abbreviated list, with an emphasis on economically important species. The following list is derived and and expanded from Taylor's Encyclopedia of Gardening (1961):
Deprecated species:
Brassica species are sometimes used as food plants by the larvae of a number of Lepidoptera species - see List of Lepidoptera which feed on Brassicas. |
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Scientific Interest: The Triangle of U Due to their agricultural importance, Brassica plants have been the subject of much scientific interest. The close relationship between 6 particularly important species (B. carinata, B. juncea, B. oleracea, B. napus, B. nigra and B. rapa) is described by the Triangle of U.
Triange of U The Triangle of U is a theory which describes the evolution and relationships between members of the plant genus Brassica.The triangle contends that many Brassica species were derived from three ancestral genomes, denoted by the letters AA, BB, or CC. Alone, each of these diploid genomes produces a common Brassica variety. The letter n denotes the number of chromosomes in each genome. For example Brassica rapa has an AA - n=10 designation. That means each cell contains two complete genome copies, (diploid) and each genome has ten chromosomes. Thus each cell will contain 20 chromosomes.
Initially, these three species would have existed as isolated relatives. But because they are so closely related it was possible for them to interbreed. This interspecific breeding allowed the creation of three new species of tetraploid Brassica. Because they are derived from the genomes of two different species, these hybrid plants are said to be allotetraploid (contain four genomes, derived from different parent species).
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This page compliments of Marisa Ciceran Created:
Thursday, December 14, 2006; Last updated:
Wednesday, January 03, 2007
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