This plant, called otot in the indigenous language of Chamorro, is endemic to three of the four largest and southernmost islands in the Mariana Archipelago: Saipan, Rota and Guam. It occurs in moist, shaded forests on limestone and also along streams on lateritic clays. The shrub is one of 50 species in this genus that occur between eastern Malesia and Polynesia. It can be easily propagated by seeds. The red, attractive, edible fruits are said to have a flavor like that of tamarind, a popular south-east asian fruit, and are likely wildlife food.

Discocalyx megacarpa is an erect shrub to 2 m with ascending brownish round branches. The lanceolate, medium-to-dark green leaves are alternate and bunched at branch tips. They occur on 1 cm petioles and are 10-22 cm long and 3-6.5 cm wide with 8-12 pairs of lateral veins. flowers occur in many-flowered panicles, usually several together with a few small leaves, on small branches. Flowers are separate sexes, and both males and females are initially white, then salmon-pink, on short (4-5 mm) pedicels. Fruits develop from female flowers and are 1 cm in diameter, thinly fleshy, red and finely ribbed, each containing one seed.