Linnaeus, Sp. Pl. 2: 667. 1753.
L. H. Bailey
Biennials or perennials;
(with slender taproot or woody caudex, becoming suffrutescent and covered with conspicuous leaf scars); (glaucous), glabrous.
branched distally, 5-10 dm.
petiole to 30 cm; blade oblong or obovate, to 45 cm × 150 mm, (fleshy), blades pinnatifid or margins dentate.
(distal) sessile; blade (oblong to lanceolate), base auriculate and amplexicaul, (margins entire).
not paniculately branched.
spreading to ascending, (8-)14-25(-40) mm.
sepals 8-15 × 1.5-2.7 mm; petals yellow, white, or lemon yellow, ovate or elliptic, (15-)18-25(-30) × (6-) 8-12 mm, claw 7-15 mm, apex rounded; filaments 8-12 mm; anthers 2.5-4 mm.
spreading to ascending, smooth, ± 4-angled or subterete, (2.5-)5-8(-10) cm × (2.5-)3-4(-5) mm; valvular segment with 10-20 seeds per locule, (2-)3-7.5(-9) cm, terminal segment usually seedless, rarely 1 or 2-seeded, (conic), (3-)4-10 mm.
brown, 1.7-2.5 mm diam.; seed coat reticulate, not mucilaginous when wetted.
Flowering May-Aug. Maritime slopes or sea-facing cliffs, weedy escape, gardens, abandoned fields, waste places; 0-100 m; introduced; Nfld. and Labr., Ont., P.E.I., Que.; Calif., Conn., Ill., Iowa, Ky., Mass., N.Y., Ohio, Pa., R.I., Tex., Vt.; Europe; Asia; Africa; introduced also in Australia.
is widely cultivated worldwide as a vegetable crop, and its various forms are generally recognized as varieties instead of subspecies; these include var.
de Candolle (kale and collards), var.
Linnaeus (cauliflower), var.
Linnaeus (cabbage), var.
Zenk (Brussels sprouts), var.
Linnaeus (kohlrabi), and var.
Plenk (broccoli). It also occurs sporadically as a weedy escape from cultivation and seems unlikely to persist for long periods of time. It is reported to be naturalized on coastal cliffs (maritime slopes) in the northern Central Coastal Region and the central and southern North Coastal Region in California (Marin, San Francisco, San Mateo, Santa Barbara, and Ventura counties) (J. T. Howell et al. 1958; Howell 1970; H. G. Baker 1972; R. C. Rollins 1993b).