1. Eruca vesicaria (L.) Cav. ssp. sativa (Mill.) Thell. (garden rocket, arugula)

E. sativa Mill.

Brassica eruca L.

Pl. 319 h, i; Map 1349

Plants annual, terrestrial. Stems (10–)20–90(–100) cm long, erect to spreading, usually few-branched from the base, sparsely pubescent with unbranched hairs. Leaves alternate and sometimes basal, (2–)4–15(–20) cm long, the lower leaves petiolate, the upper leaves sessile, not clasping, the leaf blades elliptic to oblanceolate in outline, irregularly pinnately lobed or divided with a large, terminal segment and 4–10 smaller, lateral segments, the upper leaves sometimes merely toothed, glabrous. Inflorescences panicles, the lower branches subtended by reduced leaves. Sepals (6–)7–10(–12) mm long, erect, narrowly oblong, becoming detached as the flower opens. Petals (12–)15–20(–26) mm long, not lobed, light yellow to nearly white with dark purple to brown veins. Styles 2–5 mm long at flowering, becoming elongated into a beak as the fruits mature, the stigma lobes decurrent along the upper portion of the style. Fruits ascending, straight, (11–)15–40 mm long, 5–8 times as long as wide, transversely segmented into 2 distinctly dissimilar parts, the lower portion narrowly ovoid to oblong, circular in cross-section, containing the seeds, each valve with a prominent midnerve, dehiscing longitudinally, the upper portion beaklike, (4–)5–10(–11) mm long, somewhat shorter than the lower portion, narrowly triangular, strongly flattened, seedless, indehiscent. Seeds in 2 rows in each locule, 1.7–1.9(–2.5) mm in diameter, broadly ovoid to globose, the surface with a fine, netlike or honeycomb-like pattern of ridges and pits, orange or grayish brown. 2n=22. May–October.

Introduced, uncommon and sporadic in Missouri (native of Europe, Asia, widely introduced in North America). Railroads.