Cyanea habenata is a shrub that grows to approximately 2.4 meters in height and is characterized by glabrous, branched stems. The leaves are simple and alternate, with narrowly elliptic to narrowly oblong blades measuring 11–20 cm in length and 1.4–2.3 cm in width. The leaf apex is acuminate, and the base is cuneate. The upper surfaces are dark green and glabrous, while the lower (abaxial) surfaces are light green and also glabrous. Leaf margins are callose–serrulate and often revolute. Petioles range from 2.5 to 6.8 cm in length and are glabrous. Stipules are absent. The flowers are bisexual (perfect) and are borne in axillary inflorescences of 5–10 flowers. The peduncles are 25–28 mm long and glabrous, with a short rachis measuring 4–7 mm in length. Bracts are deciduous, and the pedicels are 6–8 mm long. The hypanthium is broadly obovoid, 3–4 mm long and 2–3 mm in diameter, and glabrous. The calyx has five lobes, each about 0.5 mm long, which are deltate or shallowly deltate with acute apices; the tube is adnate to the ovary. The corolla is zygomorphic (bilaterally symmetric), white, faintly tinged with purple, and glabrous, measuring 22–28 mm in length. The corolla tube is approximately 13 mm long and 2 mm in diameter at its midpoint, gently curved, and dorsally cleft for about half of its length. The dorsal lobes are 15 mm long and 1.7 mm wide, while the ventral lobes are 11 mm long and 2 mm wide, basally connate for 6 mm; all lobes are linear with acuminate tips. The five stamens alternate with the corolla lobes and fully connate into an exserted staminal column. The filaments may be distinct or connate above, attached to the epigynous nectary disk or the base of the corolla. The filament tube is 23 mm long and glabrous, and the anther tube is about 2 mm in diameter. Dorsal anthers are 6 mm long; ventral anthers are 4.8 mm long and bear apical tufts of hairs. The anthers are dithecal, dehiscing by longitudinal slits, and may be coherent or connate to form a tube into which pollen is shed. The ovary is inferior and 2-celled with axile placentation. The stigma is 2-lobed and initially appressed and nonreceptive as the style elongates through the anther tube; it later spreads apart and becomes receptive. The fruit is a berry. It occurs in mesic to wet forest habitats.