80. Sisymbrium Linnaeus, Sp. Pl. 2: 657. 1753; Gen. Pl. ed. 5, 296. 1754.
Hedge-mustard, rocket [Latinized ancient Greek name used by Dioscorides and Pliny for various species of mustards]
Ihsan A. Al-Shehbaz
Chamaeplium Wallroth; Norta Adanson; Pachypodium Webb & Berthelot; Schoenocrambe Greene; Velarum Reichenbach
Plants not scapose; pubescent or glabrous. Stems often erect, sometimes ascending, rarely subprostrate or decumbent, often branched distally, sometimes unbranched. Leaves basal and cauline; petiolate or sessile; basal rosulate or not, petiolate, blade margins dentate, sinuate, lyrate, runcinate, or pinnately lobed [entire]; cauline similar to basal, (blade smaller distally). Racemes (several-flowered), often considerably elongated in fruit. Fruiting pedicels ascending, divaricate, or erect, slender or stout (sometimes as wide as fruit). Flowers: sepals ovate or oblong, (glabrous or pubescent); petals yellow, obovate, spatulate, oblong, or suborbicular, (longer than sepals), claw differentiated from blade, (subequaling or longer than sepals, apex obtuse or emarginate); stamens tetradynamous; filaments not dilated basally; anthers oblong, (apex obtuse); nectar glands confluent, subtending bases of stamens, median glands present. Fruits usually sessile, rarely shortly stipitate (gynophore to 1 mm), usually linear, rarely lanceolate or subulate, smooth or torulose; valves each with prominent midvein and 2 conspicuous marginal veins, usually glabrous, rarely pubescent; replum rounded; septum complete; style subclavate [clavate, conical, cylindrical]; stigma capitate (lobes not decurrent). Seeds plump, not winged, oblong [ovoid]; seed coat (reticulate or papillate), not mucilaginous when wetted; cotyledons incumbent. x = 7.
Species 41 (8 in the flora): North America, Europe, Asia, Africa; introduced in Central America, South America, Australia.
SELECTED REFERENCES Payson, E. B. 1922. Species of Sisymbrium native to America north of Mexico. Univ. Wyoming Publ. Sci., Bot. 1(1): 1-27. Rollins, R. C. 1982b. Thelypodiopsis and Schoenocrambe (Cruciferae). Contr. Gray Herb. 212: 71-102. Warwick, S. I., I. A. Al-Shehbaz, R. A. Price, and C. A. Sauder. 2002. Phylogeny of Sisymbrium (Brassicaceae) based on ITS sequences of nuclear ribosomal DNA. Canad. J. Bot. 80: 1002-1017. Warwick, S. I., C. A. Sauder, and I. A. Al-Shehbaz. 2005. Molecular phylogeny and cytological diversity of Sisymbrium (Brassicaceae). In: A. K. Sharma and A. Sharma, eds. 2003+. Plant Genome: Biodiversity and Evolution. 2+ vols. in parts. Enfield, N.H. Vol. 1, part C, pp. 219-250.
