Brassica rapa |
Brassicaceae tribe brassiceae |
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bird's rape, bird-rape, canola, common mustard, field-mustard, rape, rapeseed, turnip, turnip-rape, wild-rape, wild-turnip |
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Habit | Annuals or biennials; (roots fleshy or slender); (green to slightly glaucous), glabrous or sparsely hairy. | Annuals, biennials, or perennials [shrubs]; eglandular. |
Stems | unbranched or branched distally, 3–10 dm. |
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Basal leaves | petiole (winged), (1–)2–10(–17) cm; blade ± lyrate-pinnatifid to pinnate to pinnatisect, (5–)10–40(–60) cm × 30–100(–200) mm, (margins sinuate-dentate, sometimes ciliate), lobes 2–4(–6) each side, (terminal lobe oblong-obovate, obtuse, large, blade surfaces usually setose). |
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Cauline leaves | (middle and distal) sessile; base auriculate to amplexicaul, (margins subentire). |
petiolate or sessile; blade base auriculate or not, margins entire, dentate, serrate, or pinnately lobed. |
Racemes | not paniculately branched, (with open flowers overtopping or equal to buds). |
usually ebracteate, often elongated in fruit. |
Flowers | sepals (3–)4–6.5(–8) × 1.5–2 mm; petals deep yellow to yellow, obovate, 6–11(–13) × (2.5–)3–6(–7) mm, claw 3–7 mm, apex rounded; filaments 4–6(–7) mm; anthers 1.5–2 mm. |
actinomorphic; sepals erect, ascending, or spreading, lateral pair saccate or not basally; petals white, cream, yellow, pink, lilac, lavender, or purple, claw present, often distinct; filaments unappendaged, not winged; pollen 3-colpate. |
Fruiting pedicels | ascending to spreading, (5–)10–25(–30) mm. |
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Fruits | ascending to somewhat spreading, torulose, terete, (2–)3–8(–11) cm × 2–4(–5) mm; valvular segment with 8–15 seeds per locule, (1.3–)2–5(–7.5) cm, terminal segment seedless, 8–22 mm. |
silicles or siliques, dehiscent or indehiscent, usually segmented, usually latiseptate or terete (subterete or 4-angled in Erucastrum) [angustiseptate]; ovules (1–)2–276[–numerous] per ovary; style usually distinct (absent in Cakile, obscure in Carrichtera, obsolete in Eruca); stigma entire or strongly 2-lobed (sometimes slightly 2-lobed in Cakile). |
Seeds | black, brown, or reddish, 1.1–2 mm diam.; seed coat very finely reticulate-lightly alveolate, not mucilaginous when wetted. |
biseriate, uniseriate, or aseriate; cotyledons usually conduplicate, rarely accumbent or incumbent (in Cakile). |
Trichomes | absent or simple. |
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2n | = 20. |
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Brassica rapa |
Brassicaceae tribe brassiceae |
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Phenology | Flowering Apr–Sep. | |
Habitat | Roadsides, disturbed areas and waste places, cultivated fields, grain fields, orchards, gardens | |
Elevation | 0-1500 m (0-4900 ft) | |
Distribution |
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; Europe; Asia; Africa [Introduced in North America; introduced also in Mexico, West Indies, Central America, South America, Atlantic Islands, Australia]
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North America; Eurasia; n Africa [Introduced widely] |
Discussion | Brassica rapa is widely cultivated as an oil crop and vegetable, and cultivars, especially in Asia, have been recognized as species, subspecies, and varieties. The most important crops include: rapeseed or canola, turnip (subsp. rapa), Chinese mustard or pakchoi [subsp. chinensis (Linnaeus) Hanelt], and Chinese cabbage or petsai [subsp. pekinensis (Loureiro) Hanelt]. The species is also a widespread naturalized weed [subsp. sylvestris (Linnaeus) Janchen] throughout temperate North America and elsewhere. It is self-incompatible. Hybridization in the field in Europe has been described between B. napus and B. rapa (R. B. Jørgensen and B. Andersen 1994). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera 46, species ca. 245 (13 genera, 28 species in the flora). The generic boundaries in Brassiceae are largely artificial, and the number of genera may be substantially reduced. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 423. | FNA vol. 7, p. 419. |
Parent taxa | Brassicaceae > tribe Brassiceae > Brassica | Brassicaceae |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | B. campestris, B. campestris var. oleifera, B. chinensis, B. pekinensis, B. rapa subsp. chinensis, B. rapa subsp. pekinensis, Sinapis pekinensis | |
Name authority | Linnaeus: Sp. Pl. 2: 666. (1753) | de Candolle: Mém. Mus. Hist. Nat. 7: 242. (1821) |
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