Sisymbrium irio L.

Herb

Sisymbrium species are annual, biennial or perennial herbs, glabrous or pubescent with simple trichomes, not scapose. Rootstocks taproot. Stem usually erect, subprostrate or decumbent, ascending, simple or branched distally. Basal leaves rosulate or not, obovate-lanceolate to oblong in outline, margin lyrate pinnatifid to pinnatisect, rarely entire, apex acuminate, petiolate, cauline leaves gradually smaller, similar to basal, petiole short to sessile. Inflorescence racemes, many flowered, considerably elongated in fruit, ebracteate, rarely bracteate. Flowers bisexual, yellow, white, pink, purple, pedicel erect or reflexed, divaricate, slender or thick, ascending, sepals 4, erect or spreading, linear ovate-oblong, margin membranous, inner lateral pair base sometimes subsaccate, petals 4, obovate-oblanceolate to spathulate, margins entire, apex obtuse or emarginate, claw distinct, usually almost equal or slightly longer than sepals. Stamens 6 rarely 4, tetradynamous, filaments not dilated near the base, anthers ovate-oblong, apex obtuse rarely apiculate, nectar glands 4 confluent, usually subtending the bases of stamens, median glands present. Ovary superior, linear subcylindrical, bicarpellary, ovules 10-160. Fruit siliqua, dehiscent, linear cylindrical, sessile or rarely shortly stipitate, terete or latiseptate, smooth or torulose, valves prominent midvein and obscure marginal veins, valves chartaceous to leathery, replum rounded, septum complete, style subclavate or cylindric, stigma capitate, bilobed, lobes not decurrent. Seeds uniseriate, brown, plump, oblong-ovoid, not winged, minutely reticulate, not mucilaginous when soaked, cotyledons obliquely incumbent.

Sisymbrium 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: November—May.

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 biennial herbs, glabrous or sparsely pubescent near the base with simple trichomes, about 15-80 cm tall, not scapose. Rootstocks taproot. Stem erect, ascending, simple or divaricately branched, pubescent at the base and glabrous above. Basal leaves in rosulate or not, obovate-oblanceolate to oblong in outline, about 3-15 x 1.5-6 cm across, margins runcinate-pinnatifid to pinnatipartite, with 3-7 linear lanceolate-oblong lobes on each side, terminal lobe slightly bigger than the lateral ones, lobe margins dentate or lobed, pubescent on the margins and beneath, petiole about 1-4 cm long, cauline leaves gradually smaller, similar to basal but linear, margins 1-3 lobed or entire, petiole short to subsessile. Inflorescence raceme corymbs, 30-80 flowered, elongated in fruit, up to 25 cm long in fruit, ebracteate. Flowers bisexual, yellow, pedicel erect or reflexed, divaricate, slender, much narrower than the fruit, about 6-12 mm long, sepals 4, erect or spreading, linear oblong, cucullate, margin membranous, inner lateral pair base sometimes subsaccate, about 2-2.5 mm long, petals 4, obovate-obovate, margins entire, apex obtuse, about 2.5-3.5 x 1-1.5 mm across, claw distinct, suequalling or slightly shorter than sepals. Stamens 6, tetradynamous, filaments yellowish, not dilated near the base, about 2-4 mm long, anthers ovate-oblong, apex obtuse, about 0.5-0.8 mm long, nectar glands 4 confluent, usually subtending the bases of stamens, median glands present. Ovary superior, linear subcylindrical, bicarpellary, ovules 40-90. Fruit siliqua, dehiscent, linear subcylindrical, about 30-50 x 0.8-1.2 mm across, younger fruits overtopping the flowers, terete, erect or slightly curved inwards, valves prominent midvein, valves glabrous to torulose, replum rounded, septum complete, style subclavate or subelongate, about 0.3-0.5 mm long, stigma capitate, bilobed. Seeds uniseriate, brown, plump, oblong-ovoid, about 0.8-1 mm long, not winged, minutely reticulate, not mucilaginous when soaked, cotyledons obliquely incumbent.

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

Moist places

Roadsides, rocky places and near cultivated fields, altitude up to 2000 m.

Not evaluated (IUCN).

Used in Ayurvedic and Unani medicine.