Description from Flora of China
Plants annual, 8-50 cm tall. Stem erect, winged, upper part often curved. Leaves alternate; petiole 0.3-2 cm; leaf blade ovate or elliptic to lanceolate-elliptic, 1-10 × 1-5 cm, papery, both surfaces strigose on veins, lateral veins 4 or 5 pairs curved, base cuneate, margin serrate, teeth mucronulate, apex acute. Inflorescences axillary or terminal, 1(or 2)-flowered; peduncles 3-5 cm. Pedicels 1-1.5 cm, often sparsely strigose, 2-bracteate at base; bracts ovate, 1-2 mm. Flowers pale red-purple or white, pale purple spotted or yellow spotted. Lateral sepals ovate or obliquely ovate, ca. 4 mm, apex caudate-acute. Lower sepal saccate, 2-2.5 cm deep, gradually narrowed into an incurved spur ca. 1.5 cm; mouth vertical, 1.2-1.5 cm wide, tip acute. Upper petal subreniform, ca. 9 mm, apex cuspidate, abaxial midvein thickened, narrowly carinate; lateral united petals not clawed, ca. 1.9 cm, 2-lobed; basal lobes oblong; distal lobes oblong-dolabriform, larger, apex obtuse. Filaments compressed, 4-5.5 mm; anthers ovoid, apex acute. Ovary fusiform, ca. 3.5 mm. Capsule ca. 1.7 cm. Seeds many, brown, ellipsoid, ca. 2.5 mm, granular. Fl. Jun-Oct.
● Understories of coniferous forests on mountain slopes, grasslands; 1600-3000 m. Taiwan.