Wagner, Warren L., Derral R. Herbst and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai'i (Bernice Pauahi Bishop Museum Special Publication, 2 Vol. Set). Honolulu, HI

Flora of Hawaii:

Distribution     
Probably native to India and carried by humans throughout tropical Asia to Pacific islands because of its usefulness as a source of medicine, dye, and flavoring. In the Hawaiian Islands, a Polynesian introduction on Kaua`i, Moloka`i, Maui, Hawai`i.

Habit
Erect, deciduous, acaulescent herbs with leaf tufts 0.5-1.5 m tall, primary rhizomes usually solitary, erect, ovoid, up to 4 cm wide, internally dark yellow to orange with a paler outer area, producing thick, internally orange or dark yellow roots, secondary rhizomes abundant, usually produced in 1 plane, cylindrical, distichous, 5-10 cm long, 2-3 cm wide, with shorter lateral rhizomes.

Leaves
Leaves 5-8, blade lanceolate, oblong, or elliptic, 30-50 cm long, 8-18 cm wide, glabrous; petiole as long as or shorter than blade.  

Flowers
Inflorescences erect, synchronous with the leaves and emerging from center of leaf tuft, cylindrical, 10-20 cm long, 5-8 cm wide, fertile bracts green, ovate, 5-6 cm long, connate less than 1/2 their length, sterile bracts white and green to pink, bracteoles white with pink or green apex, 3-3.5 cm long; calyx 9-13 mm long; corolla pink to yellowish or greenish, the tube 17-24 mm long, the lobes 10-15 mm long; labellum whitish with a yellow median band, broadly obovate, 15-19 mm long and wide; lateral staminodes narrowly obovate or elliptic, 10-16 mm long; stamen ca. 6 mm long; ovary 3-celled, ovules numerous.  

Fruit
Fruit rarely produced.  

Chromosomes
2n = 32, 62 64.