Rapeseed

Brassica napus

Summary 3

Rapeseed (Brassica napus), also known as rape,oilseed rape,rapa, rappi, rapaseed (and, in the case of one particular group of cultivars, canola), is a bright yellow flowering member of the family Brassicaceae (mustard or cabbage family). The name derives from the Latin for turnip, rāpa or rāpum, and is first recorded in English at the end of the 14th century. Older writers usually distinguished the turnip and rape by the adjectives round and long (-rooted), respectively.Brassica napobrassica...

Description 4

Herbs annual or biennial, 30-150 cm tall, glabrous or basally sparsely hirsute, often glaucous, with or without fleshy taproots. Stems erect, branched above. Basal and lowermost cauline leaves long petiolate; petiole to 15 cm; leaf blade ovate, oblong, or lanceolate in outline, 5-25(-40) × 2-7(-10) cm, pinnately lobed or lyrate, sometimes undivided; terminal lobes ovate, dentate, repand, or entire; lateral lobes 1-6 on each side of midvein, much smaller than terminal one, entire, repand, or dentate, sometimes absent. Upper cauline leaves sessile, lanceolate, ovate, or oblong, to 8 × 3.5 cm, base amplexicaul, auriculate, margin entire or repand. Fruiting pedicels straight, divaricate, (1-)1.2-2.3(-3) cm. Sepals oblong, (5-)6-10 × 1.5-2.5 mm, ascending or rarely suberect. Petals bright or pale yellow, (0.9-)1-1.6(-1.8) cm × (5-)6-9(-10) mm, broadly obovate, apex rounded; claw 5-9 mm. Filaments (5-)7-10 mm; anthers oblong, 1.5-2.5 mm. Fruit linear, (3.5-)5-9.5(-11) cm × (2.5-)3.5-5 mm, terete or slightly 4-angled, sessile, divaricate or ascending; valvular segment (3-)4-8.5(-9.5) cm, 12-20(-30)-seeded per locule; valves with a prominent midvein, slightly torulose or smooth; terminal segment conical, (0.5-)0.9-1.6 cm, seedless or 1-seeded; style often obsolete. Seeds dark brown or blackish, globose, (1.2-)1.5-2.5(-3) mm in diam., minutely reticulate. Fl. Mar-Jun, fr. Apr-Jul. 2n = 38*.

Taxon biology 5

Brassica napus is an annual or biennial herbaceous plant in the Brassicaceae (the cabbage or mustard family) that includes three major categories of varieties cultivated for various edible uses:
1) rape, rapeseed, oilseed rape, or the Canadian variety canola (from the varieties napus and oleifera), used for the oil obtained from the seeds;
2) Siberian or rape kale (from the variety pabularia); used for the leaves, which are used as a cooked vegetable or for salads—although other Brassica species and varieties, including B. oleacea var. acephala also produce leafy greens known as kale; and
3) rutabagas or swedes (from the variety napobrassica), for the creamy white or yellow fleshy, turnip-like roots, which are used as a cooked vegetable, similar to turnips.

Brassica species including B. napus have such a long history of cultivation and diversification that their centers of origin are not known, and the classification of varieties and species is under constant debate and revision. B. napus was likely native to Eurasia, and is most commonly grown in northern temperate regions. It is thought to have originated as a garden hybrid between cabbage (B. olearacea var. capitata) and turnips (B. rapa var. rapa), and has been cultivated since the Middle Ages.

The diverse varieties of B. napus have different growth forms, but in general, they have glaucous (waxy) leaves that occur in a rosette, if the variety is biennial or planted late to overwinter. The leaves are pinnatifid (deeply lobed) or lyrate (deeply lobed, but with an enlarged terminal lobe and smaller lateral lobes), and are often somewhat bristly. The yellow, four-parted and cross-shaped flowers, produce a silique—a two-parted capsular fruit that dehisces (splits open) when mature—that may be up to 11 cm (4.5 in) long, each containing several hard round seeds that contain up to 40% oil.

Rapeseed oil is used for cooking and as a salad oil, as well as in mayonnaise and margarine. Siberian kale is cooked as a leafy green vegetable, or marinated and used for salads. Rutabagas, which are high in vitamin C and minerals, are hardier and easier to grow than turnips, but cooked and used in similar ways.

Statistics on the production and harvest of kale and rutabagas are lumped together with cabbages and other Brassica species, so it is hard to estimate aggregate production for all varieties this species. However, rapeseed, which has become a leading source of edible oil and is also used for biodiesel, likely accounts for the largest share of production. In 2010, the FAO estimates that total commercial production of rapeseed worldwide was 59.1 million metric tons, harvested from 31.7 million hectares. China and Canada were the leading producers of rapeseed (including canola), along with India, Germany, and France. The U.S. ranked 10th for total commercial production.

(Bailey et al. 1976, FAOSTAT 2012, van Wyk 2005.)

comments 6

cultivated

Sources and Credits

  1. (c) Marcello Consolo, some rights reserved (CC BY-NC-SA), https://www.flickr.com/photos/marcelloconsolo/14194059675/
  2. (c) Dag Terje Filip Endresen, some rights reserved (CC BY), https://www.flickr.com/photos/dag_endresen/4826067019/
  3. Adapted by Chandan Pandey from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Brassica_napus
  4. (c) Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/4964229
  5. (c) Jacqueline Courteau, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/20626860
  6. (c) Chandan Pandey, some rights reserved (CC BY-SA)

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