Cardamine maxima (Nuttall) A. Wood, Amer. Bot. & Fl. 38. 1870; Dentaria maxima Nuttall, Gen. N. Amer. Pl. 2: 66. 1818. TYPE:
Dentaria anomala Eames, Rhodora 5: 217. 1903; Cardamine anomala (Eames) Schumann, Bot. Jahresber. (Just) 31, pt. 1: 830. 1904. TYPE:
Herbs, perennial, glabrous except for leaflet margin and sometime the raceme rachis. Rhizomes fleshy, cylindrical, 3–6 mm in diam., distinctly constricted at intervals, not uniform in diam., slightly fragile, with dentate leaf scars; stolons absent. Stems 0.9–3(–4) dm, erect, simple, glabrous. Rhizomal leaves 3-foliolate, 7–20 cm; petiole 4–15 cm; terminal leaflet broadly ovate to oblong, 2–7.5 × 1.2–3.7 cm, with a petiolule 0.2–1(–1.7) cm, base cuneate to obtuse, margin coarsely dentate to sharply incised or deeply cleft into 2 or 3 lobes, the lobes dentate or incised, puberulent along margin; lateral leaflets often similar to terminal one in shape, size and margin, base often oblique, subsessile or petiolulate; cauline leaves 2 or 3, 3-foliolate, alternate or rarely subopposite; petiole (0.5–)1–4(–6.5) cm, base not auriculate; terminal and lateral leaflets resembling those of basal leaves, uppermost sometimes much smaller. Racemes ebracteate; flowering pedicels horizontal to divaricate or deflexed, 0.7–2 cm. Sepals oblong, 5–7 × 2–3 mm, erect to ascending, base of lateral pair slightly saccate; petals white or pink, oblanceolate, 1–1.7 cm × 3–6 mm, not clawed, apex rounded; median filament pairs 4–8 mm, lateral pair 3–6.5 mm; anthers linear, 1.7–2.7 mm. Fruit (undeveloped) linear-lanceolate, to 3 cm × 2 mm; valves glabrous; style 3.5–7 mm; ovules and seeds 10–14 per fruit. Seeds not known. 2n = 120, 124, 132, 138, 156, 161, ca. 208.
Flowering: Apr–Jun.
Habitat: rich woods, shady ravines, ledges, moist alluvial bottoms, steep forested slopes, ledges, stream banks.
Distribution: Canada (New Burnswick, Ontario, Quebec), United States (Connecticut, Maine, Massachusetts, Michigan, New Jersey, New York, Vermont).