Japan Flora: Stems soft-pubescent; leaves green or deep purple, long-pubesccnt beneath especially on nerves, thinly pilose above, the margins wrinkled; spikes 5-15 cm. long, rather long-pubescent; calyx 7-10 mm. long in fruit; nutlets about 1.5 mm. across. Widely cultivated.
f. viridis (Makino) Makino. Plants with margins of the leaves flat.