Impatiens laevigata var. laevigata Wall. ex Hook.f. & Thomson

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 211-212

2. Impatiens laevigata var. laevigata Wall. ex Hook.f. & Thomson — Fig. 7; Map 4; Plate 1b

Impatiens laevigata var. laevigata Wall. ex Hook.f. & Thomson (1860) 146; Hook.f. (1875) 473; (1905) 30; W.J. Kress et al. (2003) 170; Gogoi et al. (2013) 311. — Impatiens laevigata Wall. (1831) 168, nom. nud. — Type: Francis De Silva 326 ( Wall . Cat . no. 4753) (lecto, designated here K K000694815; isolecto G G00237319*, G G00237320*, K K001039825, L L2325369,M M0211761*,M M0211762*,P P04543237, P P04543244, PH PH 00015839*, S-G-33525), Sylhet (Sillet), Oct. 1820.

Impatiens rubrolineata Hook.f. (1910a) 300; Toppin (1920) 359,syn. nov.,non I. rubrolineata H. Perrier (1934) 84. — Type: Meebold 6275 (K, not found, only a specimen drawing was present ( Fig. 6)), Laimatak, 1525 m, Nov. 1907.

Impatiens purpurea­picta Hook.f. , nom. nud. in herb. — Specimens: Lace 4992 (K K000694809, K K000694810), Myanmar, N. Shan State Gokteik Gorge , 12 Nov. 1909.

Terrestrial,perennial woody shrub,glabrous, 30–100 cm tall. Stem erect, simple to richly branched, green to red. Leaves spirally arranged, crowded on the upper part. Petiole (8–) 25–70 mm long. Lamina 75–190 by 30–65 mm, elliptic, oblanceolate, to narrowly oblanceolate, apex acute to acuminate and mucronate, rarely emarginate, base attenuate to cuneate, margin shallowly serrate to shallowly crenate with minute teeth at sinus, adaxial pale green to dark green, abaxial pale green, with one pair of distinct short stalked-clavate glands on the petiole; lateral veins 5–6(–8) pairs. Inflorescence axillary, 1–4-flowered subumbellate raceme. Peduncle 8–20 mm long, with many white silica streaks. Rachis <1 mm long. Flowers 25–26 mm long, 35–40 mm deep, yellowish white, tinged with pink, slightly asymmetric. Bracts (4–)6–10 by (2–) 3–4 mm, ovate to ovate-lanceolate, apex acute, base cuneate to obtuse, margin slightly crenate, with two glands on each side of the margin, green, persistent. Pedicel (10–) 14–20 mm. Lateral sepals 4: the upper pair 12–20 by 1.5–4 mm, falcate, apex acute, base cuneate, pale yellow; the lower pair 11–12 by 3–9 mm, free, broadly ovate to orbicular, apex acute to obtuse and mucronate, base obtuse to round, margin slightly serrate with 2 pairs of glands, greenish yellow, margin slightly serrate with 2 or 3 teeth. Lower sepal 13–18 mm long, 10–12 mm deep, bucciniform, apex acute and mucronate, red inside, distal part rapidly constricted into a hooked spur, 14–22 mm long, tip swollen. Dorsal petal 15–16 by 22–23 mm, broadly elliptic to broadly obovate, apex cuspidate, base truncate, yellow, abaxial midvein with a broadly obtuse crest, 2–3 mm wide. Lateral united petals 25–26 mm long, free: the upper petals 11–12 by 11–12 mm, elliptic, yellow and pink; the lower petals c. 15 by 7 mm, obovate, apex slightly emarginate, base auricled, yellow and streaked with red lines. Stamens: filaments 8–12 mm long, pale green to pale yellow; anthers yellow. Ovary 22–38 by 18–20 mm, 4-locular. Fruits 20–22 mm long, 4–5 mm diam, cylindrical. Seeds c. 2, 3 mm diam.

Phenology — Flowering: August to December; fruiting: October to December.

Distribution — Myanmar (Kachin State), India, Bangladesh, Nepal.

Habitat & Ecology — Growing in shady areas in evergreen forest, 400–1600 m altitude.

Other collections examined. MYANMAR, Kachin State, Lace 6035 (K H2015/00092 151), Myitkyina, Trinton , alt. 600–3000 ft (183–914 m), 18 Nov.1912 ; Toppin 4300 (K H2015/00092 153), Kachin Hills, Kumtat, 1500 ft (457 m), Hologany 1350 ft (412 m), Hja Kha 1300 ft (400 m); Kingdon­Ward 7322 (K), Kingdon­Ward 7325 (K), Valley of the Nam Hat , N27°35' E97°55', alt. 2000–3000 ft (610–914 m), 20 Aug. 1926 ; Saw­Lwin KSL1026 (L), Hkakabo Razi National Park , 2015 .

Notes — Impatiens laevigata var. laevigata is very similar to I. laevigata var. grandifolia Hook.f. (1910a: 299) , an endemic to Northeast India, but differs in having yellow flowers and oblong bracts, whereas I. laevigata var. grandifolia has white-yellowish flowers, ovate to ovate-lanceolate bracts. This species is highly variable in leaf size and although Hooker (1910a) described I. laevigata var. grandifolia using the larger leaf size as a dis- tinguishing character from I. laevigata var. laevigata , we found that variation in leaf size is continuous without clear distinct size ranges.

Since there are several duplicates of Wall . Cat . no. 4753, we select the specimen Wall . Cat . no. 4753 (K000694815) as the lectotype of I. laevigata var. laevigata because it is a complete specimen with a dissected flower and also included illustration by Hooker.

Impatiens rubrolineata was distinguished from I. laevigata by Hooker (1910a), based on ovate-oblong leaves and obliquely ovate-oblong lateral sepals. The epithet ‘rubrolineata’ refers to red lines on the lower petals. However, all of those characters are also found in I. laevigata . We therefore decided to synonymize it. The holotype of I. rubrolineata, Meebold 6275, has disappeared, and only the drawing of the type was found in Kew Herbarium. It completely differs from I. rubrolineata H. Perrier (1934) , described from a specimen collected in Madagascar and renamed as I. oniveensis Eb.Fisch. & Raheliv. in Fischer & Rahilevololona (2004).