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    
Extending from Hawai`i at least to the Marquesas Islands. In the Hawaiian Islands, endemic to Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.

Habit
Coarse, glabrous perennial herbs 5-20 dm tall, rhizomes spreading close to ground level, ca. 1.5 cm in diameter, forming clumps of stems.

Leaves
Leaves rather tough and flexible, folded toward base, linear-lanceolate, 30-100 cm long, 2-3(-4) cm wide, midrib prominent and keeled, margins entire or sometimes minutely toothed. 

Flowers
Panicles (10-)20-40(-60) cm long, open or relatively narrow, branches corymbiform, 5-15 cm long, cymules 4-12(-25)-flowered, flowers secund, pedicels (3-)5-10 mm long, recurved; tepals pale blue to white, oblong-ovate, reflexed, outer ones 5-6 mm long, obscurely 5-nerved, inner ones 4-5.5 mm long, obscurely 5-nerved, the outer 2 veins obscure; filament swelling orange and turgid; anthers yellow; ovary 3-grooved. 

Fruit
Berries dark translucent blue to sky blue, obovoid to depressed-globose, often somewhat irregular, ca. 7-10 mm long. 

Seeds
Seeds 2-3(4) per cell, black, glossy, variable in shape, ranging from hemispherical, the inner face angular and with a single crest, to irregular in outline, angular and ribbed with 1 or both ends tapered, 2-3 mm long, testa crustaceous.

Chromosomes
2n = ca. 32*, ca. 40*, ca. 70*