4. Diphylleia Michaux, Fl. Bor.-Amer. 1: 203, plates 19, 20. 1803.
[Greek dis, twice, and phyllon, leaf]
Lisa O'Rourke George
Herbs, perennial, deciduous, to 12 dm, glabrous or pubescent. Rhizomes formed of distinct annual increments, producing 1 leaf or flowering shoot per year. Aerial stems present. Leaves simple, 2-parted. Leaf blade 5-47 cm, parts lobed [or not], margins prominently dentate; venation palmate. Leaves of nonflowering shoot 1, basal; petiole centrally attached, erect, stemlike; blade orbiculate, peltate. Leaves of flowering shoots 2, cauline, alternate; petiole attached to blade near margin; blade reniform-orbiculate, peltate. Inflorescences terminal, cymose or umbelliform. Flowers 3-merous, 8-20 mm; bracteoles caducous, 2, scalelike; sepals falling early, 6, white or pale green; petals 6, white; stamens 6; anthers dehiscing by 2 apically hinged flaps; pollen exine spinose; ovaries ellipsoid; placentation appearing basal; style central. Fruits berries, dark blue, ellipsoid, glaucous. Seeds 2-11, red; aril absent. x = 6.
Species 3 (1 in flora): widely disjunct temperate areas in e North America and e Asia.
Ying T. S., S. Terabayashi, and D. E. Boufford. 1984. A monograph of Diphylleia (Berberidaceae). J. Arnold Arbor. 65: 57-94.