This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Lepidium Draba L. Sp. Pl. 645. 1753.
Perennial, erect or ascending, 10'-18' high, hoary-pubescent, branched at the inflorescence. Leaves oblong or lanceolate-oblong, obtuse, slightly dentate or entire, 1 1/2'-2' long, the lower petioled, the upper sessile and clasping; pedicels slender, ascending or spreading, 3"-6" long in fruit; flowers white, about 1"-2" broad; pods very broadly ovate, or cordate, 1 1/2" long, 2" broad, arranged in short corymbose racemes; valves distinct, papillose, keeled, wingless, tipped with a slender style 1/2"-1" long.
Waste grounds, Astoria and Syracuse, N. Y., Washington, D. C, and on ballast about the seaports. Also from Colorado and Wyoming to California and British Columbia. Fugitive from Europe. Native also of Asia. April-June.
Lepidium ruderale L. Sp. Pl. 645. 1753.
Annual, erect, 6'-15' high, glabrous, wiry, freely branching. Basal and lower leaves oblong in outline, 1'-4' long, 1-2-pinnatifid into linear or oblong obtuse segments; upper leaves smaller, entire or with a few lobes; flowers i" broad or less, greenish; petals none; stamens 2; pods flat, not margined, about 1" in length, short-oval; pedicels spreading or somewhat ascending, very slender, 1 1/2"-2" long in fruit; valves sharply keeled, barely winged; seeds marginless; cotyledons incumbent.
In waste places, on ballast and along roadsides about the cities, Nova Scotia to Texas, and recorded from Bermuda. Naturalized from Europe. Has the unpleasant odor of wart-cress. Occurs also in Australia. Summer.
Lepidium virginicum L. Sp. Pl. 645. 1753.
Basal leaves obovate or spatulate in outline, generally with a large terminal lobe and numerous small lateral ones, all dentate, glabrous or slightly pubescent; stem-leaves lanceolate or oblong-linear, sharply dentate or entire, sessile, or the lower stalked; flowers 1/2"-1" broad, white, petals generally present, sometimes wanting in the later flowers; stamens 2; pedicels very slender, spreading, 2"-3" long in fruit; pod flat, short-oval or orbicular, minutely winged above; cotyledons ac-cumbent.
Lepidium densiflorum Schrad. Ind. Sem. Goett. 4.
1835. Lepidium intermedium A. Gray, Man. Ed. 2.
1856. Not A. Rich. 1847.
Much like L. ruderale and L. virginicum. Basal leaves pinnately lobed or pinnatifid. Pods obovate-orbicular to ovate, sometimes broader than long, slightly wing-margined above, about 1" in diameter; flowering pedicels ascending, forming narrow racemes, or in fruit spreading; petals small or wanting; seeds nearly wingless; cotyledons incumbent.
In dry soil, Maine and Ontario to British Columbia, Virginia, Texas and Nevada. Naturalized in Europe and native also of Asia. May-Aug. Has been confused with the Asiatic L. apetalum Willd. and with L. mŔdium Greene.
Lepidium neglÚctum Thellung, differing by slightly longer capsules with more distinctly winged seeds, is widely distributed within the range of the preceding species and is also naturalized in Europe; but it does not appear to be specifically distinct.
Lepidium sativum L. Sp. Pl. 644. 1753.
Annual, glabrous, bright green, stem slender, usually much branched, about 1° high. Lower leaves 2-pinnate, or pinnate with the segments lobed or pinnatifid, 3'-7' long, the lobes entire or incised; upper leaves sessile or nearly so, entire or incised, much smaller; flowers in loose elongated racemes, about 1" broad; petals present; stamens 6; silicles ovate-oval, about 2" high and 1" wide, equalling or longer than their pedicels, emarginate, winged all around; style short.
In waste places, Quebec to New York and British Columbia. Escaped from gardens. Native of Europe. Much cultivated for its pungent foliage. Petals often pinkish. Tongue-grass. May-Aug.