Remya montgomeryi is a weakly erect shrub, reaching approximately 1 meter in height, with leafy stems towards the apex and glabrous. The leaves are thin, narrowly elliptic, closely spaced, measuring 13-15 cm in length and 2-3.2 cm in width, with glabrous surfaces. The margins of the leaves are coarsely serrate to irregularly doubly serrate, featuring alternate teeth of varying sizes, where the larger ones are 2-3 mm long, and the smaller ones range from 0.3-1 mm. The petioles are relatively short, spanning 0.4-0.6 cm in length. The flowers are purplish-brown, erect, open panicles that can grow up to 24 cm long. The peduncles are thin, measuring 8-15 mm long. The involucre is hemispherical, 2-2.5 mm in height and 4-4.5 mm in diameter, with purple bracts slightly lacerated at the tips, ranging from acute to obtuse. Approximately 12 ray florets per head are female with vestigial rays, and the corolla is also vestigial, measuring 0.7-0.8 mm in length. These florets lack stamens and have a pappus of 4-8(-14), unequal to sometimes equal bristles. The disk florets are of two types: about 14 per head are neutral, with tubular corollas 1.2-1.3 mm long, and have lobes approximately 0.3 mm long; these florets have no stamens and a pappus consisting of 0-3(-6) somewhat flattened bristles. The inner disk florets, numbering around 35 per head, are much larger, functionally male, with campanulate corollas 2-2.2 mm long and expanded parts around 1.2 mm long; the lobes are about 0.7 mm long with fertile stamens, usually lacking a pappus. The fruits are slightly falcate achenes, 1.6-1.8 mm long, 3-4-angled, compressed, and glabrous. It grows primarily on steep, north or northeast-facing slopes or cliffs in transitional wet or dominated mixed mesic forests between 850-1,250 meters.