Impatiens acuminata Benth. ex Hook. f. & Thomson in J. Linn. Soc., Bot. 4: 145. 1860; Hook. f., Fl. Brit. India 1: 462. 1874 & in Rec. Bot. Surv. India 4: 25. 1902.

Herbs, annual, up to 60 cm high; stems simple, stout, marked below, rather fleshy, glabrous. Leaves alternate, crowded at apex, ovate-elliptic to elliptic-oblong, acuminate at apex, crenate or crenate-serrate along margins, crenations with appendages, 7.5 - 17.5 x 2 - 3 cm, glabrous, green, paler beneath; lateral nerves 4 - 8 pairs; petioles naked, 1.2 - 2.5 cm, with a red spot. Inflorescence axillary; peduncles stout, 2.5 - 3.5 cm, with red markings. Flowers 1.2 - 2.5 cm, scarlet or brick-red; pedicels erect, 1.5 - 2 cm long; bracts orbicular, obtuse or acute at apex, concave, 4 - 6 mm long, green. Lateral sepals 2, ovate-cordate, oblique, acuminate, red. Lip shallowly navicular; spur incurved, 1.5 - 2 cm long. Standard ovate, 1 - 1.5 cm long. Wings 1.5 - 2 cm long. Wings with basal lobes ovate-triangular, 5 - 8 mm; distal lobes suborbicular, 8 - 10 mm; dorsal auricle rounded. Stamens 5; anthers cohering. Ovules many; stigma sessile. Capsules erect, turgid, oblong, subacute, ca 1.3 cm long, glabrous; seeds many, arillate with spiral hairs.

Fl. June - Nov.; Fr. Sept. - Nov.

Distrib. India: E. Himalayas, 1200 - 1500 m. Arunachal Pradesh, Assam and Meghalaya.

Endemic.