39. Sisymbrium L.

Plants annual (perennial elsewhere), terrestrial, glabrous or pubescent with unbranched hairs. Stems erect to spreading, unbranched or branched. Leaves alternate and basal, short-petiolate or sessile, not clasping, the leaf blades mostly pinnately lobed or divided. Inflorescences panicles or rarely racemes, the flowers not subtended by bracts (with bracts elsewhere). Sepals linear-lanceolate to narrowly oblong, erect or ascending, green. Petals not lobed, yellow. Stamens 6. Styles 0.5–2.0 mm long. Fruits erect to spreading or ascending, more than 10 times as long as wide, linear in outline, circular in cross-section or nearly so, straight or slightly curved upward, not beaked (except for the style), the valves with a distinct midnerve and 2 less-distinct, lateral, longitudinal nerves, dehiscent longitudinally. Ovules in 1 row in each locule. Seeds 0.7–1.5 mm long, ovate to oblong in outline, somewhat flattened, not winged, the surface nearly smooth to slightly roughened or with a netlike or honeycomb-like pattern of ridges and pits, grayish yellow to orange or brown. About 40 species, Europe, Asia, Africa, introduced nearly worldwide.