Japan Flora: Stemless annual; leaves rosulate, linear, 7-20 cm. long, 4-7 mm. wide, gradually acuminate, minutely serrulate, more or less 5-veined with a number of cross veinlets; peduncles 5-7 cm. long, the spathe cylindrical, 4-5 cm. long, slightly longer than the fruit; sepals 3, lanceolate, obtuse; fruit linear; seeds ellipsoidal, about 1.5 mm. long, 0.8 mm. wide, obscurely striate with scattered tubercles. Shallow ponds and paddy fields.

Honshu, Kyu­shu. Korea, Formosa, China, India, and Australia。