Impatiens siangensis - Siang Balsam

Siang Balsam is an annual erect to prostrate, fleshy herb, sparsely branched, up to 25 cm tall. Flowers are borne singly in leaf-axils, on flower-cluster-stalks 1.5-2 cm long, greenish-purplish, bud pinkish, spur prominently curved in bud. Flowers are only partially purple with darker spots or stripes, flower-stalk is up to 1.5 cm long, pink-purplish, with a persistent bract at the base of the flower-stalk, green, ovate, 3 x 2 mm. Lateral sepals are 2, ovate to obliquely ovate, 6-8 x 5-6 mm, greenish white, flushed with pink, tip pointed, transparent, membranous. Lower sepal is boat-shaped, purplish, with straight purple streaks, tapering into a spur, up to 5 mm deep, mouth up to 8 mm wide, spur yellowish white, often purple tinged or striped, up to 2.3 cm long, linear, straight to slightly bending inward, tip white. Dorsal petal is purple, hoodlike, obovate, up to 1.2 x 0.6 cm, tip notched. Lateral united petals are purple, bilobed, unequal, without blotches, up to 1.5 x 1 cm, basal lobe unevenly triangular, up to 8 x 7 mm, clawed, tip pointed to blunt, distal lobe up to 1 x 0.7 cm, axe-shaped, tip blunt, stamen up to 6 mm. Stem is green or pinkish, round, nodes not swollen. Leaves are confined to upper portion of the stem, alternate, leaf-stalk 0.7-4.5 cm long, pinkish, with few thread-like glands, blade simple, elliptic to broadly elliptic, 1.5-7 x 1-4.5 cm, hairless, vein pairs 7-8, opposite, base wedge-shaped, tip pointed, margin rounded toothed, bristle present on the teeth towards the tip. Capsules are short, elliptic to ovate lanceshaped, swollen at middle, green, hairless, to 1.3 cm long, 4-5 mm in width. Siang Balsam is endemic to the Siang Valley of Arunachal Pradesh, and is quite common in moist areas near streams and shady forest margins at 300-600 m elevation. Flowering: June-September.