Impatiens erubescens Dunn

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 252

58. Impatiens erubescens Dunn — Map 19

Impatiens erubescens Dunn in Toppin (1920) 349; W.J. Kress et al. (2003) 169. — Type: Toppin 4362 (lecto,designated here K K000694678;isolecto K K000694721), Myanmar, Kachin State, Kachin Hills, Kao Hka gorge, Jan. 1912.

Terrestrial herb, 10–20 cm tall. Stem erect to decumbent, simple, or branched at the decumbent part, red, densely pilose to tomentose. Leaves spirally arranged. Petiole 5–17 mm long, pilose. Lamina 40–70 by 15–25 mm, lanceolate to elliptic, apex attenuate, base cuneate, margin serrate, adaxial dark green, abaxial pale red, glabrous, with 1–5 long hairs on each side of the midrib near lamina base, up to 1 mm long; lateral veins 5 or 6 pairs. Inflorescence axillary, erect, 1–3-flowered raceme. Peduncle 14–60 mm long, glabrous. Rachis 2 mm long. Flowers 32–40 mm long, 35 mm deep, pink. Bracts 2–3 by 1 mm, linear, apex acute, base cuneate, margin entire, glabrous, persistent. Pedicel 10–15 mm long, glabrous. Lateral sepals 2, 6–8 by 3 mm, free, lanceolate to ovate to elliptic, apex acuminate, base obtuse, glabrous. Lower sepal 19–25 mm long, 8–13 mm deep, bucciniform, apex acute and mucronate, glabrous, distal part gradually tapering into an incurved spur, 30 mm long. Dorsal petal 10–12 by 11 mm, orbicular to elliptic, cucullate, apex obtuse, base obtuse, glabrous, abaxial midvein with a crescent-shaped crest. Lateral united petals 25–30 mm long, free: the upper petals c. 13 by 9 mm, oblanceolate to oblong, apex truncate, base cuneate: the lower petals 16–17 by 7–8 mm,

free, ovate, apex obtuse, base with distinct auricle, c. 2 mm wide, pink with yellow auricle, glabrous. Stamens 7 mm long. Ovary 4–6 mm long. Fruits 14–15 mm long, 4 mm diam, fusiform, glabrous. Seeds c. 1 mm long.

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

Distribution — Endemic to Myanmar (Kachin State).

Ecology — Altitude 500 m.

Other collection examined. MYANMAR, Kachin State, Kingdon­Ward 7302

(K), Frontier of Tibet, Valley of the Lam Tawai , N28.0° E97.35°, 16 Aug.1926 .

Note — Impatiens erubescens can be distinguished by red pilose stems, glabrous lanceolate to elliptic leaf lamina and pink flowers. It is very similar to I. delicata but this species has a glabrous stem. It is also similar to I. khasiana but differs in having glabrous narrower leaf lamina and glabrous peduncles. We found two sheets of Toppin 4362. The K000694678 include a dissected flower, colour illustration, and handwriting, so we selected it as a lectotype.