Cyanea kuhihewa is a shrub that grows 0.35–2.25 meters tall, with erect, unbranched stems measuring 0.4–0.5 cm in diameter near the apex. The stems are tan and glabrous, with a solid pith. It has simple, alternate leaves with linear blades 31–38 cm long and 1.2–1.5 cm wide, featuring an acuminate apex, attenuate base, and glabrous surfaces that are slightly paler on the underside. The leaf margins are flat or somewhat revolute and minutely denticulate. Petioles are 2.5–3.8 cm long, representing about 1/10 to 1/12 of the lamina length, and the plant lacks stipules. The flowers are arranged in ascending 5–8-flowered inflorescences, with a peduncle 10–16 mm long and a more densely pubescent rachis 8–13 mm long. The flowers are perfect (bisexual) with pubescent pedicels 10–12 mm long. The hypanthium is obconic, 8–8.5 mm long, and sparsely pubescent. Calyx lobes are triangular, measuring 1.4–1.5 mm long and sparsely pubescent. The corolla is rose-purple, 47–53 mm long, and moderately pubescent, with a curved tube. Stamens are five in number, with a slightly exserted staminal column and a filament tube that is purple, glabrous, and somewhat curved. The ovary is inferior and 2-celled, with axile ovule placentation and a 2-lobed stigma that becomes receptive after the style grows through the anther tube. The seeds are ellipsoid, dark brown or black, 0.5–0.7 mm long, and smooth and shiny. It is found in lowland wet forest environments at 520–580 meters.