水芋 shui yu

Rhizome creeping, green, cylindric, to 50 cm, robust, 1-2(-3) cm in diam., somewhat spongy; nodes rooting. Cataphylls lanceolate, to 10 cm, apex acuminate. Petiole green, terete, (6-)12-24 cm (and longer to 30[-40] cm), base sheathing; sheath 7-8(-12) cm, with free ligule; leaf blade green, (4-)6-14 × (4-)6-14 cm; primary veins (8-)10-14(-18), pinnately arching from a strong midvein on each side, intramarginal vein inconspicuous. Peduncle green, terete, 15-30 × 0.8-1.2 cm. Spathe green outside, white inside, (3-)4-6(-8) × 3-3.5(-5) cm, apex with an acumen ca. 1 cm. Spadix 1.5-3 × 0.7-1.5 cm; stipe 5-7 mm. Flowers yellowish green, 2-2.2(-2.5) mm tall. Infructescence (2-)3-5 × (1.5-)2.5-3.5 cm. Berries red, (5-)6-12 × (4-)5-10 mm. Seed brown, 3-5 × ca. 2 mm. Fl. May-Jul, fr. Aug-Sep.

Creeping helophyte on swampy shores of streams, rivers, lakes, and ponds, forest swamps, swampy meadows, in shallow water, often with Sphagnum moss; below 1100 m. Heilongjiang, Jilin, Liaoning, Nei Mongol [Asia, N Europe, North America].