Schenkia sebaeoides is the only species of the gentian family (Gentianaceae) endemic to the Hawaiian islands. It is an annual herb about 6.0 to 20.0 cm (2.4 to 8.0 in) tall. The leaves are rather fleshy, inversely ovate or elliptic, and 0.7 to 3.2 cm (0.3 to 1.3 in) long by less than 2 cm (1 in) wide. Flowers are stalkless and are arranged along the stems near their ends. The fused sepals are 8.0 mm (0.3 in) long and are divided into uneven lobes. The white or pale pink petals are fused into a tube up to 10.0 mm (0.4 in) long, with lobes up to 4.5 mm (0.2 in) long. The cylindrical capsules are up to 9.5 mm (0.4 in) long and contain numerous tiny brown seeds.