Diplotaxis
Mém. Mus. Hist. Nat. 7: 243. 1821.
Annuals, biennials, or perennials; (sometimes suffrutescent); scapose or not; glabrous, glabrescent, or pubescent. Stems erect or ascending, branched. Leaves basal and, sometimes, cauline; petiolate or sessile; basal rosulate or not, petiolate, blade margins dentate, sinuate, or pinnatisect; cauline petiolate or sessile, blade (base not auriculate), margins entire or dentate. Racemes (corymbose, sometimes shortly bracteate basally), considerably elongated in fruit. Fruiting pedicels ascending, divaricate, or reflexed, stout to slender. Flowers: sepals ascending to spreading, oblong, lateral pair not saccate basally; petals yellow or white [purple], obovate, (apex rounded or truncate); stamens tetradynamous; filaments not dilated basally; anthers oblong to ovate, (apex obtuse); nectar glands (4): lateral cushionlike, median cylindrical. Fruits siliques, dehiscent, sessile or (long-)stipitate, segments 1 or 2, linear to linear-oblong, torulose, latiseptate or terete; (proximal segment numerous-seeded, 1-veined; terminal segment 0–2-seeded); valves glabrous; replum rounded; septum complete; ovules [12–]20–36(–46)[–276] per ovary; (style obsolete or distinct); stigma capitate or somewhat decurrent, 2-lobed. Seeds usually biseriate, rarely uniseriate, not winged, ovoid or ellipsoid; seed coat (smooth or minutely reticulate), slightly mucilaginous or not when wetted; cotyledons conduplicate. x = 7, [8, 9, 10,] 11, [13,] 21.
Distribution
Introduced; Europe, Asia, n Africa, introduced also in n Mexico, West Indies (Bahamas), Bermuda, South America, Pacific Islands (New Zealand), Australia.
Discussion
Species 25–30 (3 in the flora).
Selected References
Lower Taxa
Key
1 | Stems densely pubescent throughout; leaf blade surfaces shortly pubescent throughout; sepals pubescent, trichomes ± flexuous; petals white (turning purple); fruits: distal segment 1- or 2-seeded. | Diplotaxis erucoides |
1 | Stems glabrescent to moderately pubescent basally or distally; leaf blade surfaces glabrescent, or margins and veins glabrescent to sparsely pubescent; sepals glabrous or pubescent, trichomes straight; petals yellow; fruits: distal segment seedless | > 2 |
2 | Perennials, with adventitious buds on roots; stems frequently foliose, glabrescent or sparsely pubescent basally; fruits erect; gynophores 0.5-3 mm. | Diplotaxis tenuifolia |
2 | Annuals or perennials (short-lived), without buds on roots; stems frequently scapose, moderately pubescent; fruits erect-patent; gynophores obsolete or to 0.5 mm. | Diplotaxis muralis |