Rauvolfia sandwicensis

Rauvolfia sandwicensis, the devil's-pepper, also known as hao in the Hawaiian language, is a species of flowering plant in the milkweed family, Apocynaceae, that is endemic to Hawaii. It is a shrub, a small tree reaching 6 m (20 ft) in height, or, rarely, a medium-sized tree up to 12 m (39 ft) tall with a trunk diameter of 0.3 m (0.98 ft). Hao inhabits coastal mesic and mixed mesic forests at elevations of 100–500 m (330–1,640 ft)....read more on Wikipedia.