Haplostachys haplostachya (honohono) is a perennial woody herb in the Lamiaceae (mint) family. Square white-wooly stems grow to 30 to 50 cm (1 to 1.6 ft) long. Leaves are simple and narrowly heart-shaped, the upper surfaces of which are wrinkled and covered with downy, straight, erect hairs. Leaf margins are scalloped with shallowly rounded teeth. Inflorescences consist of large white or purple-tinged scented flowers with a prominent lower corolla lip. Flowers are arranged in a terminal main axis 10 to 30.5 cm (4 to 12 in) long, two flowers positioned at each node. Corolla tubes are 14 to 22 mm (0.9 in in) long with a convoluted aperture. Flowering occurs with terminal inflorescence emerging first and axillary inflorescences appearing sequentially for a blooming period of a few weeks. Mature fruits are dry, hard, and dark brown in color, and are obconical (cone-shaped) and three-angled.