Cyanea recta is an unbranched shrub that grows between 1 and 1.5 meters tall. The leaves are simple and alternately arranged. The blades are narrowly elliptic, measuring 12–28 cm long and 1.2–5 cm wide. The apex is acuminate, while the base is attenuate. The upper surfaces are green and glabrous, whereas the lower surfaces are white to pale green, either glabrous or pubescent. The margins are minutely callose–denticulate. The petioles range from 1.5 to 4 cm in length. Stipules are absent. The flowers occur in inflorescences with 5–7 flowers. The peduncles are 7–10 mm long, and the pedicels are 5–17 mm long. The flowers are bisexual (perfect), with an obovoid hypanthium 6–10 mm long and 3–4 mm wide and pubescent. The calyx lobes are triangular, measuring 2–2.5 mm long and 1–1.5 mm wide, with an acute apex. The corolla is purple or white with purple longitudinal stripes, measuring 30–40 mm long and 3–4 mm wide, densely pubescent. The corolla tube is suberect, with spreading lobes. There are five stamens, alternating with the corolla lobes and connate. The staminal column is glabrous or sparsely pubescent at the base. The anthers are minutely papillose, with the lower two anthers bearing apical tufts of white hairs. The ovary is inferior and two-celled, with axile ovule placentation. The stigma is two-lobed, remaining appressed and nonreceptive as the style grows through the anther tube, pushing out the pollen, after which the stigmas spread apart and become receptive. The fruit is a purple obovoid berry containing numerous seeds. It is found in mesic forests in northeastern Kauaʻi between 550-700 meters.