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 O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.

Habit
Small trees up to ca. 5 m tall; branches quadrangular, brown puberulent, but pubescence obscured by viscid exudate, the vegetative bud strap-shaped, rigid and strongly viscid-resinous, the tips becoming strongly curved and ascending. 

Leaves
Leaves few, clustered toward the tips of the branches, firm-chartaceous, elliptic to elliptic-ovate, 2.2-10.5 cm long, 1.5-5.5 cm wide, lateral veins 6-11 pairs, upper surface somewhat viscid, especially when young, puberulent on midrib toward base, lower surface dull, glabrous except with pubescent domatia in axils of lateral veins, petioles 0.2-0.7 cm long, stipules connate into a collar 2.5-4 mm long, puberulent at base.  Flowers  

Flowers
Flowers fragrant, solitary, terminal, flanked by 2 lateral vegetative buds, one of which is later surpassed by the flower, pedicels 3-5 mm long; hypanthium narrowly funnelform, 4-5 mm long; calyx narrowly funnelform, 5-8 mm long, sparsely puberulent, apically produced into 4-5 terminal spurs, these coriaceous, linear to obliquely linear-spatulate, 8-16 mm long and 1.2-2.5 mm wide at anthesis, puberulent; corolla white, thick, 6(7)-lobed, the tube 15-20 mm long (when dry), the lobes 8-18 mm long (when dry); stamens scarcely exserted; anthers 5-6 mm long.   

Fruit
Fruit green with whitish spots at maturity, subglobose or occasionally broadly ellipsoid, 2.5-3.5 cm in diameter, inconspicuously costate, pulp pale yellow.   

Seeds
Seeds straw-colored, 4-5 mm long, finely pitted.