Lepidium sativum
Sp. Pl. 2: 644. 1753.
Annuals; (often glaucous), usually glabrous, rarely sparsely pilose. Stems simple from base, erect, branched distally, (1–)2–8(–10) dm. Basal leaves (withered by anthesis); not rosulate; petiole 1–4 cm; blade 1- or 2-pinnatifid or pinnatisect (lobes ovate to oblong), 2–8(–10) cm, margins (of lobes) entire or dentate. Cauline leaves petiolate; blade similar to basal, usually less divided, rarely undivided, (distal) often linear, bases not auriculate, margins entire. Racemes considerably elongated in fruit; rachis glabrous. Fruiting pedicels suberect to ascending, appressed to rachis, straight, (terete or slightly flattened), 1.5–4(–6) × 0.4–0.6 mm, glabrous. Flowers: sepals oblong-obovate, 1–1.8 × 0.5–0.8 mm; petals white or lavender, spatulate to obovate, 2–3.5(–4) × 0.7–1.4 mm, claw 1–1.4 mm; stamens 6; filaments (median pairs) 1.5–2 mm, (glabrous); anthers 0.4–0.5 mm. Fruits broadly ovate or ovate-oblong, (4–)5–6.4(–7) × 3–4.5(–5.6) mm, apically broadly winged, apical notch 0.2 0.8 mm deep; valves thin, smooth, not veined, glabrous; style 0.1–0.5(–0.8) mm, usually included in, rarely subequaling, apical notch. Seeds (reddish brown), ovate-oblong, 2–2.7(–3) × 1–1.5 mm, (3-lobed). 2n = 16, 32.
Phenology: Flowering Apr–Aug.
Habitat: Gardens, old fields, vacant lots, disturbed areas, railroad embankments, waste grounds, roadsides, cultivated areas
Distribution
Alta., B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Conn., Idaho, Iowa, Maine, Md., Mass., Mich., N.H., N.Y., Ohio, Oreg., Pa., R.I., Tenn., Wash., Wyo., Europe, sw Asia, perhaps ne Africa, introduced also in South America (Argentina), Australia.
Discussion
Lepidium sativum is cultivated as a salad green and is sporadically naturalized, though never as an aggressive weed. It is seldom collected; the above range may be incomplete.
Selected References
None.