Chirita bicornuta Hayata, Icon. Pl. Formos. 3: 154. 1913; Didymocarpus bicornutus (Hayata) S. Y. Hu; Hemiboea merrillii Yamamoto.

Stems 20-100 cm or more, sparsely purple-brown spotted, glabrous, simple or branched, with 18 or more nodes. Petiole 2-6 cm; leaf blade sometimes oblique, elliptic to narrowly lanceolate, sometimes falcate, 7-20 X 2.5-5 cm, nearly glabrous to sparsely pubescent, base cuneate to attenuate, margin weakly serrate to nearly entire, apex acuminate, vermiform sclereids surrounding vascular bundles; lateral veins 6-10 on each side of midrib. Cymes 3- or more flowered; peduncle 1.5-4 cm, glabrous; involucre 2-2.5 cm in diam., outside glabrous. Calyx 5-sect from base; segments equal, lanceolate to narrowly elliptic, 8-12 X 3-4 mm, outside and margin glabrous. Corolla outside white, inside purple spotted, 3.7-4.5 cm, outside glabrous, inside with a ring of hairs; tube 3-3.8 cm; adaxial lip ca. 5 mm; abaxial lip ca. 7 mm. Anthers ca. 3 mm; staminodes 3, 3-8 mm. Pistil 1.5-2 cm, glabrous. Capsule 2.2-2.5 cm. Fl. Sep-Oct, fr. Nov-Dec.

Forests, shaded streamsides; 300-2200 m. Taiwan [Japan (including SW Ryukyu Islands, Iriomote Island)].