Perennial emergent or hydrophytic herb, petioles green, cylindrical, large leaves, up to 25 cm in length, 15 cm in width, deep green, variable in leaf shape. Most are obovate-lanceolate, about 10-20 cm long. Upper two petals each have two yellow-green spots. The scape is upright, usually higher than the leaf surface. The rhizome is a tufted adventitious root, 15-30 cm long, with numerous root hairs. Subterranean stem is robust, yellow-brown, with bud eyes, the stem has a cluster of leaves, plant height 80-150 cm. Petioles are green, cylindrical, with a membranous cut surface. Leaves are smooth, olive-colored, obovate-lanceolate. The base of the leaf is broadly cordate, gradually acuminate at the tip.
Panicles are terminal, 5-20 cm long, with densely packed flowers numbering over 200, blue-violet with yellow speckles, approximately 10 mm in diameter. The calyx segments are 6, nearly round, and base joined to form a tube. Fruits start green and turn brown upon ripening; the fruit skin is hard, seeds elliptical, 1-2 mm in diameter. Flowering and fruiting period: May to October.