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African mustard, Asian mustard, mustard, sahara mustard

black mustard

Habit Annuals; densely hirsute proximally, glabrescent distally. Annuals; sparsely to densely hirsute-hispid (at least basally, proximally rarely subglabrate).

usually branched basally, (widely) branched distally, (1–)3–7(–10) dm.

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

Basal leaves

(rosettes persistent);

petiole (broad) 2–10 cm;

blade lyrate to pinnatisect, 2–30 cm × 10–50(–100) mm, (margins serrate-dentate), 4–10 lobes each side.

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


blade (reduced in size distally, distalmost bractlike), base tapered, not auriculate or amplexicaul.

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).


not paniculately branched.

not paniculately branched.


sepals 5–4.5 × 1–1.5 mm;

petals pale yellow, fading or, sometimes, white, oblanceolate, 4–7 × 1.5–2(–2.5) mm, claw 1–3 mm, apex rounded;

filaments 2.5–4 mm;

anthers 1–1.3 mm;

gynophore to 1 mm.

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.

Fruiting pedicels

widely spreading, 8–15 mm.

erect (straight), (2–)3–5(–6) mm.


(shortly stipitate); widely spreading to ascending (not appressed to rachis), torulose, cylindric, 3–7 cm × 2–4(–5) mm;

valvular segment with 6–12(–15) seeds per locule, 2.2–5 cm, terminal segment 1(–3)-seeded, (cylindric, stout), 10–20 mm.

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.


light reddish brown or black, 1–1.2 mm diam.;

seed coat prominently reticulate, mucilaginous when wetted.

brown to black, 1.2–1.5(–2) mm diam.;

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


= 20.

= 16.

Brassica tournefortii

Brassica nigra

Phenology Flowering Feb–Apr. Flowering Apr–Sep.
Habitat Roadsides, waste places, old fields, washes, open desert areas intermixed with desert shrubs Roadsides, disturbed areas, waste places, fields, orchards
Elevation 0-800 m (0-2600 ft) 0-1500 m (0-4900 ft)
from FNA
AZ; CA; NV; TX; UT; Europe; Asia; Africa [Introduced in North America; introduced also in nw Mexico, Australia]
[WildflowerSearch map]
[BONAP county map]
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]

Brassica tournefortii was first reported from California (Imperial, Riverside, and western San Bernardino counties) by W. L. Jepson ([1923–1925]), with the first collections appearing from southern California in 1941 (R. C. Rollins and I. A. Al-Shehbaz 1986), Arizona in 1959 (T. H. Kearney and R. H. Peebles 1960), Nevada in 1977, and Texas in 1978 (D. E. Lemke and R. D. Worthington 1991).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.)

Source FNA vol. 7, p. 424. FNA vol. 7, p. 422.
Parent taxa Brassicaceae > tribe Brassiceae > Brassica Brassicaceae > tribe Brassiceae > Brassica
Sibling taxa
B. elongata, B. fruticulosa, B. juncea, B. napus, B. nigra, B. oleracea, B. rapa
B. elongata, B. fruticulosa, B. juncea, B. napus, B. oleracea, B. rapa, B. tournefortii
Synonyms Sinapis nigra
Name authority Gouan: Ill. Observ. Bot., 44, plate 20A. (1773) (Linnaeus) W. D. J. Koch: in J. C. Röhling, Deutschl. Fl. ed. 3, 4: 713. (1833)
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