29. Sinapis Linnaeus, Sp. Pl. 2: 668. 1753; Gen. Pl. ed. 5, 299. 1754.
Mustard [Greek sinapi, mustard]
Suzanne I. Warwick
Annuals [perennials]; not scapose; glabrous or pubescent. Stems erect, unbranched or branched distally. Leaves basal and cauline; petiolate or sessile; basal usually not rosulate, petiolate, blade margins usually lyrate, pinnatifid, or 1- or 2-pinnatisect, rarely undivided, (lobes usually coarsely dentate); cauline shortly petiolate or subsessile [sessile], blade (base not auriculate), margins often dentate or shallowly lobed [entire], rarely subentire. Racemes (corymbose, several-flowered), considerably elongated in fruit. Fruiting pedicels ascending, divaricate, or suberect [erect, reflexed], stout [slender]. Flowers: sepals usually spreading, rarely reflexed, narrowly oblong [linear], lateral pair not saccate basally; petals (spreading), yellow, obovate, claw differentiated from blade, (claw subequaling sepal, apex obtuse or emarginate); stamens tetradynamous; filaments not dilated basally; anthers oblong, (apex obtuse); nectar glands (4), distinct, lateral pair usually prismatic, rarely lobed, median pair present, (ovoid). Fruits siliques, dehiscent, sessile, segments 2, linear or lanceolate [oblong], torulose, terete or slightly flattened [4-angled, latiseptate]; (valvular segment dehiscent, longer or shorter than terminal segment, 2-5(-12)-seeded; terminal segment indehiscent, seedless or 1- [2-]seeded, flattened and ensiform, or terete and conical or subulate, sometimes corky); valves each with 3-5(-7) prominent, longitudinal veins, (thin or thick), glabrous or pubescent; replum rounded; septum complete; ovules 4-20 per ovary; stigma capitate, 2-lobed. Seeds uniseriate, usually plump, rarely slightly flattened, not winged, globose; seed coat (finely reticulate [smooth or alveolate]), mucilaginous or not when wetted; cotyledons conduplicate. x = , 9, 12.
Species 5 (2 in the flora): introduced; Eurasia, n Africa; introduced also nearly worldwide.
SELECTED REFERENCE Baillargeon, G. 1986. Eine taxonomische Revision der Gattung Sinapis (Cruciferae: Brassiceae). Doctoral thesis. Freie Universität Berlin.