Impatiens trigonosepala Hook. fil.

Plants ca. 30 cm, slender, subglabrous, with few supporting roots, simple or shortly branched at middle, basally long naked. Leaves alternate, sparse; petiole 2-4 cm; leaf blade pale green abaxially, green adaxially, 5-10 × 2-3 cm, membranous, with 1 pair of stipitate basal glands, lateral veins 5 or 6 pairs, fine, base cuneate, attenuate into petiole, margin coarsely crenate, apex shortly acuminate or acute. Inflorescences few, in upper leaf axils, 1-flowered; peduncles 3-5 cm, fibrous, glabrous or puberulent. Pedicels with lanceolate bracts at middle. Flowers pink, ca. 2.5 cm wide. Lateral sepals 2, triangular, ca. 6 × 3 mm, base truncate, apex mucronulate, abaxial midvein simple or carinate, green, glabrous or puberulent. Lower sepal navicular to funnelform, gradually narrowed into an incurved spur; spur 2-3 cm, longer than limb; mouth vertical, tip acute. Upper petal orbicular or oblate, large, ca. 1.5 cm in diam., base cordate, apex retuse, abaxial midvein narrowly carinate or not; lateral united petals ± clawed, 1.4-1.6 cm, 2-lobed; basal lobes erect or curved, small, apex entire or 2-fid; distal lobes obovate or obcordate, very large, ca. 1 cm wide; auricle inflexed. Filaments short; anthers acute. Capsule (immature) linear, ca. 2 cm. Fl. Aug.

E Sichuan.

● Shaded moist places by roadsides or canals; 1200-1300 m.

Impatiens trigonosepala adalah spesies tumbuhan yang tergolong ke dalam famili Balsaminaceae. Spesies ini juga merupakan bagian dari ordo Ericales. Spesies Impatiens trigonosepala sendiri merupakan bagian dari genus Impatiens. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh Hook.f..

Impatiens trigonosepala là một loài thực vật có hoa trong họ Bóng nước. Loài này được Hook. f. mô tả khoa học đầu tiên năm 1908.

三角萼凤仙花（学名：Impatiens trigonosepala），为凤仙花科凤仙花属下的一个植物种。