Sinapis alba L.

Sinapis species are annual or rarely perennial herbs, glabrous or pubescent with simple trichomes, not scapose. Rootstocks taproot. Stem erect, ascending, leafy, simple or branched distally. Basal leaves simple, not in rosulate, obovate-oblanceolate to oblong in outline, margin 1-2, lyrately pinnatifid to pinnatisect, lateral lobes linear, coarsely serrate, rarely entire, terminal lobe largest orbicular, petiolate, cauline leaves gradually smaller, base not auriculate, margins shallow lobed to dentate rarely subentire, petiole short to subsessile. Inflorescence raceme corymbs, many flowered, considerably elongated in fruit, ebracteate, rarely bracteate. Flowers bisexual, yellow, pedicel erect or slightly reflexed, divaricate, slender, ascending, sepals 4, erect or spreading, linear oblong, inner lateral pair base not saccate, petals 4, obovate-oblanceolate, margins entire, apex obtuse or emarginate, claw distinct, usually almost equal to sepals. Stamens 6, tetradynamous, filaments not dilated near the base, anthers oblong, apex obtuse rarely apiculate, nectar glands 4 confluent, usually subtending the bases of stamens, median glands present. Ovary superior, bicarpellary, ovules 4-20. Fruit siliqua, dehiscent, linear cylindrical, lanceolate or oblong, terete, erect or slightly curved, latiseptate, torulose, valves prominent, terminal segment indehiscent, seedless or 1-2 seeded, flattened, replum rounded, septum membranous, complete, style distinct, stigma capitate, bilobed. Seeds uniseriate, brown, plump or slightly flattened, globose-ovoid, not winged, minutely reticulate, mucilaginous or not when soaked, cotyledons conduplicate.

Sinapis species flowers are complete, bisexual, i.e., with functional male (androecium) and female (gynoecium), including stamens, carpels and ovary. Pollination is entomophilous i.e., by insects, or cleistogamy i.e., by self or allogamy i.e., by cross pollination. Flowering/Fruiting: August—December.

Seeds may be dispersed by autochory i.e., self dispersal, anemochory i.e., wind dispersal, zoochory i.e., dispersal by birds or animals, anthropochory i.e., dispersal by humans.

Annual or rarely perennial herbs, pubescent with simple trichomes or glabrous, about 25-70 cm tall, not scapose. Rootstocks taproot. Stem erect, ascending, leafy, simple or branched distally. Basal leaves simple, not in rosulate, obovate-oblanceolate to lanceolate in outline, about 5-20 x 2-6 cm across, margins 1-3, lyrately pinnatifid to pinnatisect, lateral lobes linear lanceolate to oblong, coarsely serrate, rarely entire, terminal lobe largest orbicular, petiole slender about 1-3 cm long, cauline leaves gradually smaller, oblong-ovate, base not auriculate, margins shallow lobed to dentate rarely subentire, petiole short to subsessile. Inflorescence raceme corymbs, many flowered, considerably elongated in fruit, up to 25 cm long in fruit, ebracteate, rarely bracteate. Flowers bisexual, yellow, pedicel erect or slightly reflexed, divaricate, slender or thick, about 6-12 mm long, sepals 4, erect or spreading, linear oblong, inner lateral pair base not saccate, about 4-6 x 1-2 mm across, petals 4, obovate, margins entire, apex obtuse or emarginate, about 8-12 x 4-6 mm across, claw distinct, usually almost equal to sepals. Stamens 4-6, tetradynamous, filaments not dilated near the base, anthers oblong, apex obtuse rarely apiculate, nectar glands 4 confluent, usually subtending the bases of stamens, median glands present. Ovary superior, bicarpellary, ovules 4-20. Fruit siliqua, dehiscent, linear cylindrical, lanceolate or oblong, about 15-35 x 3-4.5 mm across, sessile, valvular segment terete or slightly compressed, latiseptate, torulose, trichomes of two types, valves 3-7, hispid, prominent, terminal segment indehiscent, seedless or 1-2 seeded, flattened, replum rounded, septum membranous, complete, style distinct, stigma capitate, bilobed. Seeds 1-5 in each locule, uniseriate, brown, plump or slightly flattened, globose-ovoid, about 2-3 mm long, not winged, minutely reticulate, mucilaginous or not when soaked, cotyledons conduplicate.

Sinapis species are susceptible to various insect pests, virus, mildews and moulds.

Roadsides, waste places and near cultivated fields.

Not evaluated (IUCN).

Used in Ayurvedic and Siddha medicines.