Wagner, Warren L., Derral R. Herbst and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai

Flora of Hawaii:

Distribution     
In the Hawaiian Islands, endemic to Kaua`i.

Habit
Shrub, 0.5-2.5 m tall; stems 4-12 mm in diameter, moderately leafy toward apex; latex white. 

Leaves
Leaves 8-19 cm long, 2.0-5.5 cm wide, oblanceolate, elliptic, or narrowly elliptic; margin serrulate or crenulate; apex acute or acuminate; base cuneate or attenuate. Petiole 2.0-6.5 cm long, 1/4-1/2 as long as lamina. Flowers  

Flowers
Racemes 5-20-flowered; peduncle 3-20 mm long; rachis 5-30 mm long; bracts 0.8-2.7 mm long, glabrous (rarely becoming foliaceous, oblanceolate, 18-30 mm long, 3.5-7.0 mm wide, acute at apex, attenuate at base); pedicels 8-13 mm long. Hypanthium 4-6 mm long, 3.5-4.5 mm in diameter, ca.1/6 as long as corolla, broadly ellipsoid or obovoid. Calyx lobes 0.5-1.0 mm long, 0.5-0.7 mm wide, glabrous. Corolla 14-24 mm long; tube 10-14 mm long, 1.5-2.0 mm tall at base, 3.0-4.2 mm tall above middle; dorsal lobes 4-11 mm long, 0.8-1.5 mm wide, 2/3 as long to almost as long as tube; ventral lobes 7-10 mm long, 1.0-1.5 mm wide. Filament tube 12-20 mm long; anther tube 1.7-1.9 mm in diameter, short-pubescent at base; dorsal anthers 4.5-5.0 mm long, 1/4-3/10 as long as filament tube; ventral anthers 3.5-4.0 mm long, with tufts of hairs 1.0-1.5 mm long at apex.   

Fruit
Berry 5-12 mm long, 5-11 mm in diameter, globose or ellipsoid.   

Seeds
Seeds 0.7-1.2 mm long, 0.5-0.8 mm wide.  

Chromosomes
n = 14