- Scientific Name: Tripterospermum filicaule (Hemsley) Harry Smith
- Ref: Notes Roy. Bot. Gard. Edinburgh. 26: 238. 1965.
- Synonym: Gentiana filicaule Hemsley in F. B. Forbes & Hemsley, J. Linn. Soc., Bot. 26: 127. 1890.
- Chinese Common Name: 细茎双蝴蝶 xìjīng shuāng∙húdié
- Family: Gentianaceae A. L. Jussieu
- Genus: Tripterospermum Blume
- Distribution: Forests; ca.350-3000 m. Yunnan, Guizhou, eastern Sichuan, western Hubei, Hunan, Shaanxi, southern Gansu, eastern Henan, Anhui, Zhejiang, Fujian, northern Guangdong, western Guangxi.
- Photo: 11/24/2018, Lin’an
Stems spirally twisted, twining, slender, terete, striate. Basal leaves cespitose; petiole ca. 1 cm, slender; leaf blade ovate, (2-)3-5 × 1-2 cm, base truncate, margin crenulate, apex acuminate to acute, veins 3 and distinct. Stem leaves with petiole (0.5-)1-2 cm, slender; leaf blade lanceolate, ovate-lanceolate, or ovate, (3-)4-11 × 1.5-3(-4.5) cm, base rounded, subcordate, or truncate, margin crenulate, apex acuminate, veins 3-5. Inflorescences 1-flowered; bracts 1-4 pairs, linear to lanceolate. Pedicel 3-11 mm. Calyx campanulate; tube 6-12 mm, narrowly winged; lobes linear to linear-lanceolate, 5-12 mm, apex acuminate. Corolla pink, blue, or violet, narrowly campanulate, 4-5 cm; lobes ovate-triangular, 5-7 mm, apex acute; plicae triangular to semiorbicular, 1.5-2 mm, margin crenulate. Filaments linear, 1.6-2.2 cm; anthers ellipsoid, ca. 1.5 mm. Disc ca. 1 mm. Style linear, 1.2-1.5 cm. Mature fruit unknown. Fl. and fr. Sep-Jan. (Flora of China)