Remya montgomeryi is a small short-lived perennial shrub, about 1.0 m (3.3 ft) tall, with many sprawling to weakly erect, smooth branches that are glabrous. The leaves are narrow, up to about 15 cm (6 in) long, and are bunched at the ends of the branches. The leaves are coarsely toothed along the edges, and are green on the upper surface. The lower surface is green in R. montgomeryi, while in the other two species (R. kauaiensis and R. mauiensis) it is covered with a dense mat of fine white hairs.