Ochrosia haleakalae, a member of the Apocynaceae (dogbane) family, is a tree 2 to 8 m (7 to 26 ft) tall. Elliptical leaves are simple, smooth, deep green with a yellowish midrib and conspicuous secondary venation, with three to four leaves per node. As with all members of the Apocynaceae, this species has milky sap. Five-petaled flowers are perfect, fragrant, and pale greenish-white, arising from leaf axils near the terminal ends of branches. Petals curl slightly backwards. Stamens are inserted on the corolla tube just below the mouth of the flower but are not exserted. Flowers of O. haleakalae have two ovaries that give rise to two adjacent drupaceous (succulent fruit with a single seed enclosed by a stony layer in the fruit wall (i.e., endocarp) (e.g., peaches and olives)) fruits that are ovoid to lanceoloid-ellipsoid (broadest near the base and somewhat concavely attenuate to the apex), 4 to 6 cm (1.6 to 2.4 inches (in) long, and yellow to brown-streaked when ripe. Fruits develop irregular ridges at maturity due to differential thickening of the exocarp.