1. L. Michaùxii, Torr. Scapes 2–6´ high; leaf-lobes usually numerous (7–15); petals purplish or nearly white with a yellowish base, obtuse; pods not torulose, oblong to linear (6–15´´ long); style short.—S. Ind to Tenn. and Mo.
2. L. torulòsa, Gray. Similar, but pods torulose even when young, linear; style 1–2´´ long; seeds acutely margined rather than winged; petals emarginate.—Barrens of Ky. and Tenn.
3. DENTÀRIA, Tourn. Toothwort. Pepper-root.
Pod lanceolate, flat, as in Cardamine. Style elongated. Seeds in one row, wingless, the stalks broad and flat. Cotyledons petioled, thick and very unequal, their margins somewhat infolding each other.—Perennials, of damp woodlands, with long, horizontal, fleshy, sometimes interrupted, scaly or toothed rootstocks, of a pleasant pungent taste; the simple stems leafless below, bearing 2 or 3 petioled compound leaves about or above the middle, and terminated by a single corymb or short raceme of large white or purple flowers. Flowers larger, pods broader, and seeds larger than is usual in Cardamine. (Name from dens, a tooth.)
[*] Rootstock elongated; leaves 3-foliolate.
1. D. diphýlla, L. Rootstock long and continuous, often branched, toothed; stem-leaves 2, similar to the radical ones, close together; leaflets rhombic-ovate or oblong-ovate, shortly petiolate, coarsely crenate, the teeth abruptly acute; petals white.—Rich woods, Maine to Minn. and Ky. May.—Rootstocks 5–10´ long, crisp, tasting like Water-Cress.
[*][*] Rootstock tuberous, more or less moniliform; leaves 3-foliolate or 3-parted.
2. D. laciniàta, Muhl. Tubers deep-seated, usually not jointed nor prominently tubercled; root-leaves often none; stem-leaves 3-parted, the lateral segments often 2-lobed, all broadly oblong to linear, more or less gash-toothed; flowers white or rose-color.—N. Eng. to Minn., Kan., and southward. April, May.—Var. multífida, a slender form with the narrowly linear segments usually more or less divided into linear lobes. (D. multifida, Muhl.) Southward, scarcely if at all within our limits.
3. D. heterophýlla, Nutt. Tubers near the surface, jointed, narrowly oblong or thick-clavate, prominently tubercled; leaves 3-foliolate, the leaflets distinctly petiolate, oblong-lanceolate to linear, entire to rather deeply crenate, rarely laciniate or lobed; root-leaves with ovate or lanceolate and usually lobed leaflets.—Penn. to Ky. and southward. Blooming a little later than the last.
4. D. máxima, Nutt. Tubers jointed, strongly tubercled; stem-leaves usually alternate, 3-foliolate; leaflets ovate or oblong-ovate, coarsely toothed and somewhat cleft or lobed.—Vt. to western N. Y. and Penn. May.
4. CARDAMÌNE, Tourn. Bitter Cress.
Pod linear, flattened, usually opening elastically from the base; the valves nerveless and veinless, or nearly so; placentas and partition thick. Seeds in a single row in each cell, wingless; their stalks slender. Cotyledons accumbent, flattened, equal or nearly so, petiolate.—Mostly glabrous perennials, leafy-stemmed, growing along watercourses and in wet places. Flowers white or purple. (A Greek name, in Dioscorides, for some cress, from its cordial or cardiacal qualities.)
[*] Root perennial; leaves simple.
1. C. rhomboídea, DC. (Spring Cress.) Stems upright from a tuberous base and slender rootstock bearing small tubers, simple; root-leaves round and often heart-shaped; lower stem-leaves ovate or rhombic-oblong, somewhat petioled, the upper almost lanceolate, sessile, all often sparingly toothed; pods linear-lanceolate, pointed with a slender style tipped with a conspicuous stigma; seeds round-oval.—Wet meadows and springs; common. April–June.—Flowers large, white.
Var. purpùrea, Torr. Lower (4–6´ high), and usually slightly pubescent; flowers rose-purple, appearing earlier.—Along streams in rich soil. Western N. Y. to Md. and Wisc.
2. C. rotundifòlia, Michx. (Mountain Water-Cress.) Stems branching, weak or decumbent, making long runners; root fibrous; leaves all much alike, roundish, somewhat angled, often heart-shaped at the base, petioled; pods small, linear-awl-shaped, pointed with the slender style; stigma minute; seeds oval-oblong.—Cool shaded springs, N. J. (Middletown, Willis) to Ky., and southward along the mountains. May, June.—Flowers white, smaller than in n. 1.
3. C. bellidifòlia, L. Dwarf (2–3´ high), alpine, tufted; leaves ovate, entire, or sometimes with a blunt lateral tooth (4´´ long), on long petioles; pods 1´ long, upright, linear; style nearly none, stout.—Summits of the White Mountains and Katahdin, Maine. July.—Flowers 1–5, white. (Eu.)
[*][*] Root perennial; leaves pinnate; flowers showy.
4. C. praténsis, L. (Cuckoo Flower.) Stem ascending from a short rootstock, simple; leaflets 7–13, those of the lower leaves rounded and stalked, of the upper oblong or linear, entire, or slightly angled-toothed; petals (white or rose-color) thrice the length of the calyx; pod 9–15´´ long, 1´´ broad; style short.—Wet places and bogs, Vt. to N. J., Wisc., and northward; rare. May. (Eu.)
[*][*][*] Root mostly biennial or annual; leaves pinnate; flowers small, white.
5. C. hirsùta, L. (Small Bitter Cress.) Glabrous or beset with scattered hairs; stems (3´–2° high) erect or ascending from the spreading cluster of root-leaves; their leaflets rounded, those of the upper leaves oblong or linear and often confluent, all either toothed, angled, or entire; pods linear, very narrow, erect or ascending; style variable.—Wet places; common. May–July. The ordinary form corresponds closely to the European var. sylvática, Gaud. The typical imperfectly developed annual form, with only 4 stamens and rather strict pods, occurs very rarely. A form answering to C. parviflora of Europe, with mostly linear leaflets and pods often erect on spreading pedicels, is occasionally found in drier localities. (Eu., Asia.)
5. ÁRABIS, L. Rock Cress.
Pod linear, flattened; placentas not thickened; the valves plane or convex, more or less 1-nerved in the middle, or longitudinally veiny. Seeds usually margined or winged. Cotyledons accumbent or a little oblique.—Leaves seldom divided. Flowers white or purple. (Name from the country, Arabia. See Linn. Phil. Bot. § 235.)
§ 1. ARABIS proper. Seeds in one row in each cell, orbicular or nearly so, more or less wing-margined; cotyledons strictly accumbent.
[*] Low, chiefly biennials, diffuse or spreading from the base.
1. A. Ludoviciàna, Meyer. Nearly glabrous, often annual; leaves all pinnately parted into oblong or linear few-toothed or entire divisions, those of the lower leaves numerous; pedicels very short; flowers small, white; pods rather broadly linear, spreading, flat; seeds winged.—Open grounds, Va. to Mo., and southward.
[*][*] Erect and simple leafy-stemmed biennials, with simple leaves, white or whitish flowers, narrow but flattened ascending or erect pods, and nearly wingless seeds.
2. A. pàtens, Sulliv. Downy with spreading hairs, erect (1–2° high); stem-leaves oblong-ovate, acutish, coarsely toothed or the uppermost entire, partly clasping by the heart-shaped base; petals (bright white, 4´´ long) twice the length of the calyx; pedicels slender, spreading; pods spreading or ascending, tipped with a distinct style.—Penn. to central Ohio and southward; Minn. April, May.
3. A. hirsùta, Scop. Rough-hairy, sometimes smoothish, strictly erect (1–2° high); stem-leaves oblong or lanceolate, entire or toothed, partly clasping by a somewhat arrow-shaped or heart-shaped base; petals (greenish-white) small, but longer than the calyx; pedicels and pods strictly upright; style scarcely any; immature seeds somewhat 2-rowed.—Rocks, common, especially northward. May, June. (Eu.)
[*][*][*] Erect and simple leafy-stemmed biennials (1–3° high), with small whitish flowers, recurved-spreading or pendulous