Pod roundish, much flattened contrary to the narrow partition; the valves boat-shaped and keeled. Seeds solitary in each cell, pendulous. Cotyledons incumbent, or in n. 1 accumbent! Flowers small, white or greenish. (Name from λεπίδιον, a little scale, alluding to the small flat pods.)—Ours are annuals or biennials, except the last.
[*] Leaves all with a tapering base, the upper linear or lanceolate and entire, the lower and often the middle ones incised or pinnatifid; pods orbicular or oval, with a small notch at the top; the style minute or none; stamens only 2.
1. L. Virgínicum, L. (Wild Peppergrass.) Cotyledons accumbent and seed minutely margined; pod marginless or obscurely margined at the top; petals present, except in some of the later flowers.—June–Sept. A common roadside weed, which has immigrated from farther south.
2. L. intermèdium, Gray. Cotyledons incumbent as in the following; pod minutely wing-margined at the top; petals usually minute or wanting; otherwise nearly as in n. 1.—Dry places, from western N. Y. and N. Ill., north and westward.
L. ruderàle, L. More diffuse, the smaller and oval pods and the seeds marginless; petals always wanting.—Roadsides, near Boston, Philadelphia, etc.; not common. (Adv. from Eu.)
[*][*] Stem-leaves with a sagittate partly clasping base, rather crowded.
L. campéstre, Br. Minutely soft downy; leaves arrow-shaped, somewhat toothed; pods ovate, winged, rough, the style longer than the narrow notch.—Old fields, Mass. and N. Y. to Va.; rare. (Nat. from Eu.)
L. Dràba, L. Perennial, obscurely hoary; leaves oval or oblong, the upper with broad clasping auricles; flowers corymbose; pods heart-shaped, wingless, thickish, entire, tipped with a conspicuous style.—Astoria, near New York, D. C. Eaton. (Adv. from Eu.)
21. SENEBIÈRA, DC. Wart-Cress. Swine-Cress.
Pod flattened contrary to the narrow partition; the two cells indehiscent and falling away at maturity from the partition as closed nutlets, strongly wrinkled or tuberculate, 1 seeded. Cotyledons narrow and incumbently folded transversely. Low and diffuse or prostrate annuals or biennials, with minute whitish flowers. Stamens often only 2. (Dedicated to J. Senebier, a distinguished vegetable physiologist.)