Impatiens porrecta Wall. ex Hook.f. & Thomson, 1831

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 251-252

57. Impatiens porrecta Wall. ex Hook.f. & Thomson — Map 19; Plate 4d

Impatiens porrecta Wall.ex Hook.f.& Thomson (1860) 116,138. — Impatiens porrecta Wall. (1831) 245, nom. nud.; Hook.f. (1875) 472; (1904) 29, 31; Toppin (1920) 352. — Type: Wall . Cat . no. 7275 (lecto, designated here K K001127061), Sylhet.

Impatiens bella Hook.f.& Thomson (1860) 116,138; Hook.f.(1875) 458,syn. nov. — Type: Griffith s.n. (lecto, designated here K K000694775), Khasia.

Terrestrial, annual herb, 10–20 cm tall. Stem erect to procumbent, 1–2.5 mm diam, branching in the decumbent part, densely pilose especially towards apex, sometimes nearly glabrous on the lower part. Leaves spirally arranged. Petiole 8–25 mm long, 1–1.5 mm diam, densely pilose with 1 or 2 pair(s) of glandular hairs on petiole. Lamina 21–45 by 10–28 mm, ovate to elliptic to obovate, apex acute to obtuse, base obtuse to cuneate to attenuate, margin serrate to cuneate, abaxial densely to remotely pilose, adaxial remotely pilose and densely pilose at veins to glabrous, with or without 1 pair of glands near lamina base; lateral veins 5–8 pairs. Inflorescence axillary, erect, 1–3-flowered raceme. Peduncle 7–35 mm long, c. 1 mm diam, densely pilose. Rachis absent– 2 mm long, c. 1 mm diam, densely pilose. Flowers 15–25 mm long, 20–40 mm deep, yellow. Bracts 2–4 by 1–2 mm, linear to lanceolate, apex acute, base cuneate, margin entire, densely pilose, persistent. Pedicel 10–15 mm long, <1 mm diam, pilose to densely pilose. Lateral sepals 2, 6–9 by 2.5–5 mm, free, ovate to narrowly ovate, apex acute to acuminate, base obtuse to cuneate, pilose to densely pilose. Lower sepal 9–15 mm long, 6–15 mm deep, bucciniform, apex acuminate, with dark red reticulated lines, pilose to remotely pilose, distal part rapidly constricted into a curved to incurved spur, 17–30 mm long. Dorsal petal 9.5–12 by 8–11 mm, elliptic to orbicular, cucullate, apex round to emarginate, base obtuse, pilose, abaxial midvein with a crescent-shaped to a keel-shaped crest. Lateral united petals 16.5–20 mm long, free: the upper petals c. 8 by 7 mm, obovate, apex truncate, base cuneate; the lower petals c. 10 by 6–8 mm, free, ovate, apex obtuse, base auricled. Stamens c. 5 mm long. Ovary 5 mm long, c. 1 mm diam, pilose. Fruits 12 mm long, c. 1 mm diam, fusiform, pilose. Seeds unknown.

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

Distribution — Myanmar (Chin State, Kachin State); India (Assam State, Manipur State, Meghalaya State); Laos (Muang Curm).

Ecology — Growing along streams or in humid areas of evergreen forest, 600–1600 m altitude.

Other collections examined. INDIA, Lobb s.n. (syn K), Khasia; Hooker & Thomson 92 (syn of Impatiens bella K,L L2326061,L L2326062,L L2326063, MPU019010*), Khasia, near to Kalapane, alt. 4000–5000 ft, 6 Aug. 1850 . – MYANMAR, Chin State, Venning 84 (K), Chin Hills, Minkin, 29 July 1910 ; Kachin State, Toppin 4359 (K 2 sheets), Kachin Hills, Kao Hka Gorge and Ngau Hka; Lace 6043 (E E00752854,E E00752855,E E00752856,K), Myitkyina district , Wabaukyer,dongyakyer, 1500–2500 ft, 20 Nov. 1912 ; Kingdon­Ward 20780 (BM), the north triangle, Hkinkum, alt. 4000 ft, 6 May 1953; Kingdon­Ward 21131 (BM),ibid., 9 July 1953 ; Kingdon­Ward 21227 (BM),ibid., 3 Aug.1953 ; Kingdon­Ward 7315 (K), N27°45' E97°55', alt. 5000–6000 ft, 19 Aug. 1926.

Notes — In the protologue, Hooker & Thomson (1860) mentioned that I. porrecta is similar to I. bella but that it differs in having multiple flowers on one peduncle (instead of one flower in I. bella ). However, we found that this character is variable within I. porrecta , and no other characters provide a distinction between I. bella and. I. porrecta . The lateral sepals also vary from glabrous to densely pilose.

Map 19 Distribution of Impatiens putaoensis Y.H.Tan, S.S.Zhou & B.Yang (●), I. porrecta Wall.ex Hook.f. & Thomson (●) and I. erubescens Dunn (●).

Impatiens porrecta is also morphologically similar to I. khasiana and I. putaoensis but differs in having yellow instead of purple or white flowers.

The specimen Wall . Cat . no. 7275 (K001127061) is designated as lectotype of I. porrecta as it is the only specimen we found. It matches the protologue and was determined by Hooker as I. porrecta Wall.

Hooker & Thomson (1860) described I. bella as glabrous and listed the specimens that Hooker & Thomson collected from Kalapane. They mentioned at least three specimens for I. bella in the protologue. We designate the specimen Griffith s.n. (K000694775) as lectotype because it is in good condition and completely matches the protologue