4. N. palústre, DC. (Marsh Cress.) Stem erect; leaves pinnately cleft or parted, or the upper laciniate; the lobes oblong, cut-toothed; pedicels about as long as the small flowers and mostly longer than the oblong, ellipsoid, or ovoid pods; style short.—Wet places or in shallow water; common. June–Sept.—Flowers only 1–1½´´ long. Stems 1–3° high.—The typical form with oblong pods is rare. Short pods and hirsute stems and leaves are common. Var. híspidum is a form with ovoid or globular pods. (Eu.)
§ 3. Petals white, much longer than the calyx; pods ovoid or globular; leaves undivided, or the lower ones pinnatifid; root perennial.
5. N. lacústre, Gray. (Lake Cress.) Aquatic; immersed leaves 1–3-pinnately dissected into numerous capillary divisions; emersed leaves oblong, entire, serrate, or pinnatifid; pedicels widely spreading; pods ovoid, 1-celled, a little longer than the style.—Lakes and rivers, N. E. New York to N. J., Minn., and southwestward. July–Aug.—Near N. amphibium.
N. Armoràcia, Fries. (Horseradish.) Root-leaves very large, oblong, crenate, rarely pinnatifid, those of the stem lanceolate; fruiting pedicels ascending; pods globular (seldom formed); style very short. (Cochlearia Armoracia, L.)—Roots large and long; a well-known condiment. Escaped from cultivation into moist ground. (Adv. from Eu.)
12. BARBARÈA, R. Br. Winter Cress.
Pod linear, terete or somewhat 4-sided, the valves being keeled by a mid-nerve. Seeds in a single row in each cell, marginless. Cotyledons accumbent.—Mostly biennials, resembling Nasturtium; flowers yellow. (Anciently called the Herb of St. Barbara.)
1. B. vulgàris, R. Br. (Common Winter Cress. Yellow Rocket.) Smooth; lower leaves lyrate, the terminal division round and usually large, the lateral 1–4 pairs or rarely wanting; upper leaves obovate, cut-toothed, or pinnatifid at the base; pods erect or slightly spreading; or in var. stricta, appressed; in var. arcuàta, ascending on spreading pedicels.—Low grounds and roadsides; apparently introduced, but indigenous from L. Superior northward and westward. (Eu.)
B. præ̀cox, R. Br. (Early Winter C.), with 5–8 pairs of lateral lobes to the leaves, and longer pods on very thick pedicels,—yet probably only a variety of the other,—somewhat cultivated from N. Y. southward as a winter salad, under the name of Scurvy-Grass,—is beginning to run wild. (Eu.)
13. HÉSPERIS, Tourn. Rocket.
Pod linear, nearly cylindrical; stigma lobed, erect. Seeds in 1 row in each cell, oblong, marginless. Cotyledons incumbent.—Biennial or perennial, with serrate sessile or petiolate leaves, and large purple flowers. (Name from ἑσπέρα, evening, from the evening fragrance of the flowers.)