Impatiens violiflora Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 240-241

41. Impatiens violiflora Hook.f. — Map 15; Plate 3g

Impatiens violiflora Hook.f.(1875) 457 (as ‘ Impatiens violaeflora ’); (1905) 26, 32; Toppin (1920) 352;T. Shimizu (1970) 198; W.J. Kress et al. (2003) 170; Wu (2006) 76. — Impatiens violiflora Hook.f. in Craib (1926b) 214. — Type: Lobb s.n. (lecto, designated here K K000694901), Myanmar, Mon State, Moulmain (Mawlamyine).

Impatiens aureliana Hook.f. (1908) t. 2851; (1909) 7; (1911a) 616;Y.L. Chen et al. (2007) 58,syn.nov. — Type: Prince d’Orléans s.n. (holo P00780659), Indo-Chine, 30 June 1892.

Terrestrial, annual herb, up to 50 cm tall. Stem erect, c. 6 mm diam, moderately branched, green, glabrous to pilose towards apex. Leaves spirally arranged, sometime decussate to subopposite at the lower nodes. Petiole up to 20 mm long, c. 2 mm diam, cylindrical, green to red, with many glandular hairs, pilose. Lamina up to 75 by 30 mm, ovate to ovate-oblong, apex acute to acuminate, base attenuate, margin serrate, papyraceous, green pilose on both sides, with many glandular hairs at the margin in basal third of the leaf; lateral veins 6 or 7 pairs. Inflorescence axillary, erect, 1- or 2-flowered fascicle. Flowers c. 25 mm long, pink. Pedicel c. 35 mm long, c. 1 mm diam, green, pilose. Bracts c. 2 by 1 mm, linear, apex acute, pink, pilose. Lateral sepals 2, c. 2 by 1 mm, free, ovate, apex acute, base cuneate, brownish green, glabrous. Lower sepal c. 7 by 7 mm, 6 mm deep, navicular, apex mucronate, base obtuse, pinkish white, pilose outside, dorsal part abruptly constricted into a narrow slightly incurved spur, up to 32 mm long, pink with dark pink tip. Dorsal petal c. 14 by 22 mm, broadly obcordate, flat, apex emarginate, base round, pink, glabrous to pilose on midrib, abaxial midvein with narrow crest, green tip. Lateral united petals free: the upper petals 12 by 8 mm, obovate, apex obtuse to truncate, base cuneate, pink; the lower petals c. 13 by 8 mm, free, obovate, apex obtuse, pink, with yellow spot at the base, glabrous. Stamens: filaments c. 3 mm long, white; anthers purple. Ovary c. 3 mm long, 5-locular, green, pilose. Fruits c. 15 mm long, c. 8 mm diam, fusiform, 5-lobed, green, pilose. Seeds 6–8.

Phenology — Flowering: June to December; fruiting: July to December.

Distribution — Myanmar (Kachin State, Mandaly Region, Shan State, Kayin State, Tanintharyi Region), China (Yunnan Province), Thailand (Chiang Mai, Chiang Rai, Prae, Kanchanaburi, Tak), Vietnam.

Ecology — Growing in open areas, along roadsides in evergreen forest or mixed deciduous forest, abundant when present, 550–1450 m altitude.

Other collections examined. MYANMAR, Kachin State, Buchanan 4 (E E00752726,K H2015/00092 161), Myitkyina,Suma Hills,alt. 3000–4000 ft (914 m), 30 Nov.1910; Buchanan 5565 (K H2015/00092 164, H2015/00092 165),Myitkyina,Suma Hills, near side of Irawaddy,alt. 3500–5000 ft, 29 Oct. 1911; Toppin 2679 (K), Sinlum; Keenan et al. 3899 (RAF7466/3, 2 sheets), Sumprabum subdivision, N26°40' E97°20',alt. 5000–7000 ft, Mar.1962; Mandalay Region, Lace 5496 (E E00752727;K H2015/00092 163, H2015/00092 166), Pyin Oo Lwin district (Maymyo), Anisakarn falls, alt. 2500 ft, 15 Oct. 1911; Ruchisansakun 759 (L L2071189, L L2071190), Mogok, Mogok along the roadside, N22°54'10.9" E96°23'53.0", alt. 1390 m, 22 Nov. 2015; Ruchisansakun 762 (L L2071199,L L2071200,L L2071201,L L2071202),Mogok, Mintatar quarter, N22°55'03.7" E96°28'39.6", alt. 1134 m, 23 Nov. 2015; Lace 5983 (E E00752725,E E00752728,K H2015/00092 162), Ruby Mines district (Mogok), Wapundaung, alt. 1000–5000 ft; Daw Nilar Khin & Daw Nu Nu Yee 31 (RANG), Yamethin district, Momi Taung, 16 Oct. 2002; Shan State, Ruchisansakun 723 (L L2071099, L L2071100, L L2071101, MAND, RAF, RANG), Taunggyi district, N20°50'59.09" E97°14'13.67" and Lomkok mountain, N20°49'03.45" E97°13'28.19", alt. 1169–1191 m, 20 Sept. 2015.

Note — In previous studies, populations from Myanmar and Thailand were identified as I. violiflora , whereas populations from China and Indochina were identified as I. aureliana ( Hooker 1911a, Chen et al. 2007). However, I. aureliana cannot be distinguished morphologically from I. violiflora . It seems to have smaller flowers, but we observed that I. violiflora is characterized by extensive size variation with regard to both floral and vegetative parts, even within the same population. Furthermore, the long red hairs and glands at the base of the lamina and petioles were mentioned as distinct characters of I. aureliana , but we also found these in I. violiflora (Wu 2006) . Hence, we decided to synonymize I. aureliana under I. violiflora . Hooker (1875) did not designate a type I. violiflora . We found only Lobb s.n. (K000694901), which matches the protologue. Hence, we designate it as lectotype. For I. aureliana , we believe that specimen P00780659 is the holotype because it is the only specimen that matches the protologue and the drawing on this specimen is exactly similar to the illustration in the protologue ( Hooker 1908).