Herbs large, 1.5-2 m tall, stout. Rhizomes and roots stout. Stem hollow, sulcate, subglabrous or muricate on nodes. Petiole of basal leaf terete, ca. as long as blade, densely papilliferous; leaf blade large, ca. as long as wide, 40-60 cm, abaxially densely pubescent, adaxially sulcate to papilliferous, basal veins 5, base cordate, palmately divided into pinnatisect lobes, apex acuminate or narrowly acute. Stem leaves smaller above; ocrea large, to 15 cm, outside muricate. Panicle large; branches connivent, densely pubescent. Pedicel 2-2.5 mm, jointed below middle. Flowers small. Tepals 6, purple-red, rarely yellow-white, outer 3 elliptic to orbicular, smaller, 1-1.5 mm. Stamens not exceeding perianth. Ovary rhomboid-ovoid; style slightly deflexed; stigma inflated. Fruit oblong-ellipsoid to oblong, 8-9 × 7-7.5 mm, both ends retuse; wings ca. 2.5 mm wide, with longitudinal veins near margin. Seeds brown-black, broadly ovoid. Fl. Jun, fr. Aug.