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black mustard

Habit Annuals; sparsely to densely hirsute-hispid (at least basally, proximally rarely subglabrate). Annuals, biennials, or perennials [shrubs]; eglandular.
Stems

usually branched distally, (widely spreading), 3–20 dm.

Basal leaves

petiole to 10 cm;

blade lyrate-pinnatifid to sinuate-lobed, 6–30 cm × 10–100 mm, lobes 1–3 each side, (smaller than terminal, terminal lobe ovate, obtuse).

Cauline leaves

sessile or subsessile;

blade (ovate-elliptic to lanceolate, similar to basal, reduced distally and less divided), base tapered, not auriculate or amplexicaul, (margins entire to sinuate-serrate).

petiolate or sessile;

blade base auriculate or not, margins entire, dentate, serrate, or pinnately lobed.

Racemes

not paniculately branched.

usually ebracteate, often elongated in fruit.

Flowers

sepals 4–6(–7) × 1–1.5 mm;

petals yellow, ovate, 7–11(–13) × (2.5–)3–4.5(–5.5) mm, claw 3–6 mm, apex rounded;

filaments 3.5–5 mm;

anthers 1–1.5 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

erect (straight), (2–)3–5(–6) mm.

Fruits

erect-ascending (± appressed to rachis), smooth, ± 4-angled, 1–2.5(–2.7) cm × (1.5–)2–3(–4) mm;

valvular segment 2–5(–8)-seeded per locule, (0.4–)0.8–2(–2.5) cm, terminal segment seedless (linear, narrow), (1–)2–5(–6) 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

brown to black, 1.2–1.5(–2) mm diam.;

seed coat coarsely reticulate, minutely alveolate, not mucilaginous when wetted.

biseriate, uniseriate, or aseriate;

cotyledons usually conduplicate, rarely accumbent or incumbent (in Cakile).

Trichomes

absent or simple.

2n

= 16.

Brassica nigra

Brassicaceae tribe Brassiceae

Phenology Flowering Apr–Sep.
Habitat Roadsides, disturbed areas, waste places, fields, orchards
Elevation 0-1500 m (0-4900 ft)
Distribution
from FNA
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; NB; NL; NS; ON; PE; QC; SK; Europe; Asia; Africa [Introduced in North America; introduced also in Mexico, Central America, South America, Atlantic Islands, Australia]
[WildflowerSearch map]
[BONAP county map]
North America; Eurasia; n Africa [Introduced widely]
Discussion

Brassica nigra is widely cultivated as a condiment mustard. It is also a cosmopolitan weed especially common in the valleys of California (R. C. Rollins 1993). It occurs only sporadically in southern Canada but most frequently in Ontario and along the St. Lawrence River. Specimens from Alberta, Arkansas, Delaware, and South Carolina have not been observed.

(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. 422. FNA vol. 7, p. 419.
Parent taxa Brassicaceae > tribe Brassiceae > Brassica Brassicaceae
Sibling taxa
B. elongata, B. fruticulosa, B. juncea, B. napus, B. oleracea, B. rapa, B. tournefortii
Subordinate taxa
Synonyms Sinapis nigra
Name authority (Linnaeus) W. D. J. Koch: in J. C. Röhling, Deutschl. Fl. ed. 3, 4: 713. (1833) de Candolle: Mém. Mus. Hist. Nat. 7: 242. (1821)
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