Brassica tournefortii Gouan
Family: Brassicaceae
Asian Mustard,  more...
[Brassica tournefortii var. sisymbrioides (Fisch.) Grossh.]
Brassica tournefortii image

Annuals; densely hirsute proximally, glabrescent distally. Stems usually branched basally, (widely) branched distally, (1-) 3-7(-10) 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. Cauline leaves sessile; blade (reduced in size distally, distalmost bractlike), base tapered, not auriculate or amplexicaul. Racemes not paniculately branched. Fruiting pedicels widely spreading, 8-15 mm. Flowers: 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. Fruits (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. Seeds light reddish brown or black, 1-1.2 mm diam.; seed coat prominently reticulate, mucilaginous when wetted. 2n = 20.

Flowering Feb-Apr. Roadsides, waste places, old fields, washes, open desert areas intermixed with desert shrubs; 0-800 m; introduced; Ariz., Calif., Nev., Tex., Utah; Europe; Asia; Africa; introduced also in nw Mexico, Australia.

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).

AZGF 2005--, Al-Shehbaz 2014 (Jepson Online)

Duration: Annual

Nativity: Non-Native

Lifeform: Forb/Herb

General: Introduced exotic, coarse winter annual with well-developed taproot, stems simple to many-branched above, flowering branches spreading, 30-120 cm; lower part of plant hirsute with coarse, rough white hairs, especially lower leaf surfaces, veins and margins.

Leaves: Basal rosette 15-30 cm, petioled, pinnatifid with the terminal lobe usually largest, or leaves of stunted plants often obovate and merely toothed; stem leaves reduced upwards.

Flowers: Sepals 3.5-4 mm, pale, almost translucent, drab purple-brown, slightly swollen basally; petals, stamens, and stigma pale yellow; petals 6-8 mm, corolla bilaterally symmetrical.

Fruits: Silique on pedicel 12-16 mm, spreading; silique linear, terete, 2.1-2.4 mm wide, 3.7-6 cm long with well-developed beak 11-14 mm; finely netted inside.

Ecology: Found in open, sandy soils, waste ground and disturbed sites below 3,000 ft (914 m); flowers January-June.

Distribution: Native to Mediterranean, sw Asia; Naturalized in the US from CA and s NV to TX

Notes: One of the most widespread exotics in the region. Think daikon radish in appearance, only with a much smaller root.

Ethnobotany: Unknown

Etymology: Brassica is the Latin name for cabbage, tournefortii is named for Joseph Pitton de Tournefort (1656-1708).

Synonyms: Brassica tournefortii var. sisymbrioides

Editor: SBuckley, 2010