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.

Habit
Erect, suffrutescent perennial herbs 0.75-1.5 m tall, with horizontal or ascending lateral branches.

Leaves
Leaves pinnately compound or some simple, usually 6.5-13 cm long including petiole, leaflets (1-)3-5(-7), ovate-lanceolate, usually 4-11 cm long, 2-5 cm wide, glabrous or glabrate, margins serrate. 

Flowers
Heads 10-30 in compound cymes terminating lateral branches only, 1.5-2.5 cm in diameter including ray florets, peduncles 0.8-2 cm long, glabrous or glabrate; outer involucral bracts 3-6 mm long, the inner ones distinct; ray florets 4-5(6) per head, sterile, rays yellow, 8-12 mm long, 4-5 mm wide; disk florets 10-25 per head, perfect, corollas yellow; pappus of 1-2 awns 0.5-1.5 mm long, rarely absent. 

Fruit
Achenes black, curved or twisted ca. 1 revolution or less, wingless, 7-15 mm long, 0.8-1.7 mm wide, glabrous.