Plants annual, 20-70 cm tall. Stem erect, stem and branches purple or red-brown spotted. Leaves often crowded at apex of stem, or remote, alternate; petiole 2.5-4.5 cm; leaf blade oblong or oblong-lanceolate, 6-15 × 2.5-5.5 cm, with few ciliate glands at basal margin, lateral veins 7-9 pairs, base cuneate, margin crenate, apex caudate-acuminate. Inflorescences axillary, 1-4-flowered. Pedicels slender, bracteate at base; bracts linear. Flowers purple-red, ca. 1.5 cm deep or larger. Lateral sepals 4; outer 2: linear-lanceolate; inner 2: linear. Lower sepal saccate, abruptly narrowed into an incurved short spur. Upper petal broadly reniform, apex emarginate, abaxial midvein carinate, cristate above middle; lateral united petals not clawed, 2-lobed; basal lobes elliptic; distal lobes oblong-dolabriform; auricle suborbicular. Anthers obtuse. Capsule linear. Fl. Jul-Aug, fr. Sep-Oct.

● Forests on slopes, forest margins, grasslands, along water edges, shaded moist places; 800-1800 m. Chongqing, Gansu, Guizhou, Henan, Hubei, Hunan, Shaanxi, Shanxi, Sichuan.