Impatiens graciliflora Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 220-221

12. Impatiens graciliflora Hook.f. — Map 7

Impatiens graciliflora Hook.f. (1905) 15; Fedde (1905) 432. — Type: Pantling 64I (lecto, designated in Akiyama (2018) K K000694665), India, Sikkim, Lenchul, alt. 6000 ft, Aug. 1903.

Annual herb, 40–50 cm tall. Stem erect, 3–4.5 mm diam, simple to rarely branched, glabrous. Leaves spirally arranged. Petiole absent – 15 mm long, c. 1 mm diam, glabrous. Lamina 73–135 by 19–40 mm, elliptic to ovate-lanceolate to lanceolate, apex acute to acuminate, base attenuate, margin serrate, glabrous, a single stipulate gland at the base of petiole and adnate to the stem; lateral veins 10–12 pairs. Inflorescence terminal, erect, 20–28-flowered, verticillate raceme, 3- or 4-flowered at each node. Peduncle 36–55 mm long, c. 1 mm diam, glabrous. Rachis 45–90 mm long, slender, glabrous. Flowers c. 13–15 mm long, c. 20 mm deep, pink. Bracts 3–6 by c. 1 mm, lanceolate, apex aristate with long awns, base cuneate to obtuse, margin entire, glabrous, persistent. Pedicel 14–20 mm long, slender, glabrous. Lateral sepals 2, 4–5 by 1 mm, free, falcate, apex aristate with long awns, 1.5–3 mm long, base cuneate, glabrous. Lower sepal 4–5.5 mm long, 34–37 mm deep including spur, navicular, apex mucronate, glabrous, tapering into a long straight spur, c. 30 mm long, single tip. Dorsal petal 4.5–6 by 4–7 mm, ovate to broadly elliptic, cucullate, apex mucronate, base obtuse, glabrous to remotely pilose, abaxial midvein simple or with a narrow crest terminating in a short acute point.

Lateral united petals 12–14 mm long, free: the upper petals, c. 2 by 1.5 mm, elliptic, apex round, base obtuse; the lower petals 10.5–11 by 5.5–6.5 mm, ovate-triangular, apex obtuse, base slightly auricled, glabrous. Stamens: filaments c. 3 mm long; anthers obtuse. Ovary c. 3 mm long, glabrous. Fruits 18–18.5 by 1.5–2 mm, linear to clavate, glabrous; fruiting pedicels up to 20.5 mm long.

Phenology — Flowering: August; fruiting: August.

Distribution — Myanmar (Kachin State), India (Sikkim State).

Ecology — Unknown, 1500–1850 m altitude.

Other collections examined. MYANMAR, Kachin State, Kingdon­Ward 6700 (K), Seinghku-Adung confluence, 9 May 1926; Toppin 2776 (K H 2015/00092 21; K H 2015/00092 22; sheet 3; sheet 4; BM), Sinlum .

Note — Impatiens graciflora is very similar to I. radiata but differs in having a longer spur. The spur length of I. radiata is rather variable, but it is never as long as in this species.