Cyanea superba subsp. superba is a palm-like tree that grows 4–6 meters tall. Its leaves are simple and alternate, with oblanceolate blades measuring 50–100 cm long and 10–20 cm wide. The leaf apex is acute, the base is cuneate, and the surfaces are glabrous or densely pubescent on the lower side. The margins are callose-crenulate, and the petioles are 5–8 cm long. The inflorescence comprises 5–15 flowers hanging below the leaves and densely pubescent. The peduncles are 200–350 mm long, with 2–6 mm long pedicels and oblanceolate bracts 12–45 mm long. The flowers are bisexual (perfect) and have an obconical hypanthium 10–16 mm long. The calyx lobes are narrowly oblong, 6–16 mm long. The corolla is whitish or cream with purple veins, 55–80 mm long, and 7–11 mm wide, densely pubescent, with the lobes being ¾ as long to as long as the tube. It has five stamens, with a glabrous staminal column and glabrous anthers, the lower two of which have apical tufts of white hairs. The ovary is inferior, 2-celled, with axile ovule placentation, and the stigma is 2-lobed, becoming receptive after the anther tube pushes out the pollen. The fruit is yellow to orange, obovoid, 16–22 mm long, and 10–16 mm wide, and it contains numerous seeds. It is found in mesic forests on O’ahu at elevations of 580–610 meters.