Impatiens sinlumiensis Grey-Wilson

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 231

26. Impatiens sinlumiensis Grey-Wilson — Map 11

Impatiens sinlumiensis Grey-Wilson (1989c) 714; W.J. Kress et al. (2003) 170. — Type: Toppin 2777 (holo K K000694937; iso BM, K K000694934, K K000694935,K K000694936), Myanmar,NE Burma, Kachin Hills,Sinlum, alt. 1700–1800 m.

Impatiens cymbifera sensu Toppin (1920) 362, non Hook.f. (1875) 474.

Terrestrial, annual herb, 10–20 cm tall. Stem erect, branched in the lower part, glabrous. Leaves spirally arranged. Petiole 7–58 mm long, glabrous. Lamina 58–116 by 17–62 mm, ovate to elliptic to lanceolate-elliptic, apex acuminate to acuminatecaudate, base attenuate, margin serrate to crenate, adaxial glabrous or glabrous with short hairs on the veins, abaxial glabrous, with one pair of globose glands on each side of petiole base; lateral veins 9–13 pairs. Inflorescence axillary to subterminal, erect, (6–)11–17-flowered raceme. Peduncle 50–90 mm long, glabrous. Rachis 12–20 mm long. Flowers 16–19 mm long, 26–36 mm deep, asymmetric, mauve, marked with dark purple. Bracts 7.5–12 by 7–10 mm, ovate, concave, completely covering the young flower, apex acute to acuminate, base obtuse to round, margin entire, without glands, glabrous, caducous. Pedicel 14.5–25 mm long, glabrous. Lateral sepals 2, 6.5–7.5 by 3.5–4 mm wide, free, obliquely ovate, apex acuminate and long mucronate, base obtuse, glabrous. Lower sepal 10–12.5 by 10–11 mm, bucciniform, apex acute and mucronate, glabrous, dorsal part gradually tapering into a straight or curved spur, 16–21 mm long, slightly bifid. Dorsal petal 8.5–9 by 7.5–8 mm, ovate to elliptic, flat, apex obtuse to round, base cuneate to obtuse, glabrous, abaxial midvein simple. Lateral united petals 20 mm long, free: the upper petals 6–9 by 4–5 mm, falcate to triangular-ovate, apex obtuse, base cuneate; the lower petals 11–17 by 2.5–4 mm, free, narrowly elliptic, base without auricle, glabrous. Stamens: filaments unknown. Ovary unknown. Fruits 16–17(–29) mm long, c. 1.5 mm diam, linear, glabrous. Seeds unknown.

Phenology — Flowering:August to September; fruiting: September.

Distribution — Endemic to Myanmar (Kachin State).

Ecology — Montane forest, in damp shady places along streamsides, 1700–1800 m altitude.

Note — The specimens of I. sinlumiensis were previously identified as I. cymbifera by Toppin, but Grey-Wilson (1989c) noticed that they constitute a different species and described it as a new species, I. sinlumiensis .