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    
In the Hawaiian Islands, endemic to Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.

Habit
Trees or rarely shrubs up to 15 m tall; young branches 2-4 mm in diameter toward apex, glabrous except above stipule scars.

Leaves
Leaves chartaceous to subcoriaceous, elliptic to obovate, (1.5-)3-15 cm long, (1-)4-5.5(-8) cm wide, secondary nerves 7-10 on each side of midrib, both surfaces usually glabrous, domatia somewhat elevated, porate, subglabrous, often scattered over blade, or sometimes absent, apex acute to obtuse, base acute to long-attenuate, petioles (5-)10-25(-50) mm long, sometimes winged distally, glabrous, stipules ovate to lanceolate, strongly imbricate in bud, 7-22 mm long, 4-9 mm wide, acute to acuminate, upper surface villous toward base, lower surface glabrous or slightly pubescent toward apex. 

Flowers
Flowers perfect or functionally unisexual, 4(5)-merous; staminate and perfect flowers (1-)3-7 in cymes, peduncles (22-)30-120 mm long, 1-2(-3) mm wide, often strongly compressed, usually erect, calyx limb funnelform to tubular, truncate to broadly 2-lobed and boat-shaped, 1-5 mm long, usually glabrous, corolla salverform, the tube (5-)7.5-10(-12) mm long, 1.5-2.5 mm wide, glabrous externally, pubescent toward base within, the lobes 4-5 mm long, 2.5-4 mm wide, obtuse to rounded, anthers sessile in corolla throat, 3-5 mm long, up to 0.8 mm wide, abortive ovary up to 4 mm long, 2-celled (or 4-celled in perfect flowers?), style subterete, up to 5 mm long, glabrous, stigmas 2, linear, up to 1.5 mm long; pistillate flowers solitary or 3 in cymes, peduncles (22-)30-60(-100) mm long, up to 2(-3) mm wide, often compressed, erect, calyx limb as in staminate flowers, corolla funnelform to salverform, the tube 6-9 mm long, 1.5-3 mm wide, staminodia ca. 2.5 mm long, ovary globose, ca. 2.5 mm long, (6-)8-12-celled, style 6.5-9.5 mm long, stigmas 8-12, linear, unequal, 0.5-2.5 mm long, exserted. 

Fruit
Fruit depressed-subglobose or often laterally compressed, 6-20 mm in diameter, pyrenes (2-)8-12.