Cyanea profuga is an unbranched shrub that grows to 1.8–2.4 meters tall. Its leaves are simple and alternate, with elliptic blades measuring 18–24 cm in length and 7–10 cm in width, featuring an acuminate apex and cuneate base. The leaf surfaces are glabrous, and the margins are callose–dentate. The petioles are 8–12.5 cm long, and the plant lacks stipules. It produces inflorescences of 9–12 flowers, with peduncles measuring 25–40 mm and pedicels 8–10 mm long. The flowers are bisexual and perfect, with an oblong to obconical hypanthium 6–7 mm long and 3–4 mm wide. The calyx lobes are oblong, measuring 3–5 mm in length and 1–2 mm in width, with a rounded and apiculate apex. The corolla is white, 30–35 mm long and 2–3 mm wide, glabrous, with a suberect tube and spreading lobes that are ¾ as long to as long as the tube. The stamens are connate with a glabrous staminal column, and the anthers are glabrous with apical tufts of white hairs on the lower two. The ovary is inferior and 2-celled, with axile ovule placentation. The stigma is 2-lobed, transitioning from nonreceptive to receptive as the style extends through the anther tube during pollination. The fruit are orange berries. It is found in lowland mesic and montane wet ecosystems on Molokai.