Cyanea kuhihewa is a shrub in the bell flower family (Campanulaceae), 0.4 to 2.3 m (1.2 to 7.4 ft) tall with unbranched erect stems 0.4 to 0.5 cm (0.2 in) in diameter. Leaves are glabrous, 31 to 38 cm (12 to 15 in) long, 1.2 to 1.5 cm (0.5 to 0.6 in) wide, and slightly paler below. Inflorescences are ascending (growing obliquely upward), 5- to 8-flowered, with a peduncle (flower stalk) 10 to 16 mm (0.4 to 0.6 in) long and sparsely pubescent (with soft hairs). Calyx lobes are triangular, 1.4 to 1.5 mm (0.06 in) long, and 0.9 to 1.1 mm (0.04 in) wide. The corolla (flower petals) is rose-purple with lobes edged in white, 47 to 53 mm (1.9 to 2.1 in) long, with a curved tube 28 to 33 mm (1.1 to 1.3 in) long and 5.3 mm (0.2 in) at the base. Seeds are ellipsoid, dark brown or black, 0.7 to 0.8 mm (0.03 in) long, and 0.3 to 0.4 mm (0.01 to 0.02 in) wide, smooth, and shiny.