Impatiens duclouxii Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 233

30. Impatiens duclouxii Hook.f. — Map 12

Impatiens duclouxii Hook.f. (1908) 245; Grey-Wilson (1989b) 121; Y.L. Chen et al. (2007) 64. — Type: Henry 11080 (lecto, designated in Grey-Wilson (1989b) K K000694006), China, Yunnan Province, Mentse, alt. 8500 ft (2591 m).

Impatiens jurpioides T. Shimizu (1969) 39, syn. in Grey-Wilson (1989b). — Type: Iwatsuki et al. T9687 (holo KYO; iso A00051220*,BKF,SHIN, SING, G0062204), Thailand, Chiang Rai, Doi Pa Hom Pok, below the summit of Doi Pa Hom Pok , northwest of Phan , alt. 2000–2350 m, 13 Sept. 1967 .

Terrestrial, perennial with woody stem, 40–50 cm tall. Stem erect, up to 2.5 mm diam, unbranched, glabrous. Leaves spirally arranged. Petiole 24–35 mm long, c. 1 mm diam, glabrous. Lamina 110–122 by 44–47 mm, ovate, apex acuminate, base attenuate, margin serrate with teeth, adaxial pilose, with 2 pairs of glands at leaf base; lateral veins 8 or 9 pairs. Inflorescence axillary, pendulous, 6-flowered. Peduncle 18–20 mm long, <1 mm diam, glabrous. Rachis up to 31 mm long, <1 mm diam. Flowers c. 34 mm long, c. 44 mm deep. Bracts 2–3 by 1.5 mm, ovate, apex acute and mucronate, base obtuse, margin entire, without glands, glabrous, persistent. Pedicel c. 16 mm long, <1 mm diam, glabrous. Lateral sepals 2, c. 8 by 5 mm, obliquely ovate, free, apex acute and mucronate, base cuneate, glabrous. Lower sepal 19–20 mm long, 19–22 mm deep, deeply bucciniform, apex acuminate, glabrous, abruptly constricted into a spiral spur, c. 7–10 mm long. Dorsal petal c. 15 by 20 mm, broadly elliptic, cucullate, apex shallowly cordate, base obtuse, glabrous, abaxial midvein with acute appendage, c. 10 mm long. Lateral united petals 28–32 mm long, free: the upper petals 15–16 by 7–10 mm, ovate, apex obtuse, base cuneate; the lower petals 15–20 by 12–13 mm, free, obovate, apex obtuse, glabrous. Fruits c. 20 mm long, cylindrical. Seeds unknown.

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

Distribution — Myanmar (Kachin State), China (Yunnan Province), Thailand (Chiang Mai Province).

Ecology — Growing in shady areas in mixed deciduous forest or broad-leaved evergreen forest, 1900–2200 m altitude.

Other collections examined. CHINA, Fr. Ducloux 2613 (syn P P04614775, P P04614778), Yunnan; Delavay s.n. (syn K K000694005, P P04614773, P P04614774, P P04614776), Pee tsao long, 1895; Henry 12559 (syn B B100365159*, E E00313630, K K000694007, K K000694008, NY NY00387525*), Szemao, alt. 5000 ft; Henry 9267 (syn K K000694004), Mengtsze, alt. 7000 ft (2134 m), 1898 . – MYANMAR, Kachin State, Kaulback 410 (BM), Hkawng Gaw, N25°58' E98°00',alt. 2500 ft (762 m), 12 Sept.1939; Toppin 2745 (K), Kachin Hills, Sinlum, 13 Aug. 1912, alt. 1980–2130 m; Armstrong et al. 1153 (NY2687903), Putao district, Naungmung Township, Hkakabo Razi National Park ,between Ta Pai rest house and Aliaung village , N27.6704° E98.1456°, alt. 983 m, 30 Oct. 2015 .

Note — Impatiens duclouxii belongs to the Impatiens jurpia complex ( Grey-Wilson 1989b). It is very similar to I. jurpia Buch.- Ham. ex Hook.f. & Thomson ( Hooker & Thomson 1860: 140) but differs in having a shorter peduncle (shorter than 22 mm). It is also similar to I. kathmanduensis Grey-Wilson (1989b: 119) but differs from that species in having a longer dorsal petal appendage (longer than 4 mm). In Myanmar, it is most similar to I. chimiliensis but differs from it in having a shorter peduncle, a shorter rachis and a spur that ends in a hook or spiral.

Section Uniflorae Hook.f. & Thomson (1860) 113