Impatiens striolata Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 249-251

55. Impatiens striolata Hook.f. — Map 18

Impatiens striolata Hook.f. (1905) 28, 33. — Type: Hooker & Thomson 91 (lecto, designated here K K000694624; isolecto P P04543679), India, Khasia Hills, alt. 4000–5000 ft (1524 m) .

Annual herb, 20–40 cm tall. Stem erect, seldom decumbent in the lower part, up to 4 mm diam, unbranched to rarely branched, red, glabrous. Leaves spirally arranged. Petiole 11–30 mm long, c. 1 mm diam, glabrous. Lamina 37–60 by 17–30 mm, ovate to elliptic, apex acute to acuminate, base attenuate to cuneate, margin serrate to slightly serrate, adaxial remotely pilose, green with red margin, abaxial glabrous, with one pair of glands on each side of margin near lamina base; lateral veins 6–9 pairs. Inflorescence axillary, erect, 1- or 2-flowered raceme. Peduncle 12–17 mm long, reddish green, glabrous. Rachis 20 mm long, red, glabrous. Flowers 25–31 mm long, 27–29 mm deep, yellow with red stripes and red spur. Bracts 2–3 by 1 mm, linear to narrowly lanceolate, apex acute, base cuneate, margin entire, without glands, red, glabrous, persistent. Pedicel 10–12 mm long, red, glabrous. Lateral sepals 2, 2–3.3 by 1.3–1.5 mm, free, ovate to lanceolate, apex acuminate, base obtuse, red, glabrous. Lower sepal 13.5–17 mm long, 7–10 mm deep, bucciniform, apex acute and mucronate, yellow to orange with red stripes, glabrous, gradually narrowed into an incurved spur, strongly incurved at half the length, tip straight,

Fig. 19 Impatiens putaoensis Y.H.Tan, S.S a. Habit; b. front view of flower; c. lateral d. lateral sepals;e. lower sepal; f. dorsal petal petals. — Drawn by Saroj Ruchisansakun.

18–20 mm long, red with yellow tip. Dorsal petal 11.5–12 by 10.5–12 mm, broadly ovate to broadly elliptic, apex emarginate and mucronate, base obtuse to truncate, yellow with deep red near the midrib, glabrous, abaxial midvein with a keel-shaped crest, 1–1.5 mm long. Lateral united petals 25–28 mm long, free: the upper petals 11–13 by 7–9 mm, obovate, apex acute to acuminate, base cuneate, yellow with red marks near the base; the lower petals 14–22 by 7.5–8 mm, free, ovate, apex acute to obtuse, base with distinct auricles, 1.5 mm long, round, glabrous. Stamens: filaments c. 5.2 mm long; anthers obtuse. Ovary c. 5 mm long. Fruits c. 14 mm long, 3 mm diam, fusiform, glabrous. Seeds unknown.

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

Distribution — Myanmmar (Chin State), India (Asssam State).

Ecology — Growing along streams in exposed areas of evergreen forest, 1500–2400 m altitude.

Other collections examined. MYANMAR, Chin State, Mu Mu Aung & Law Shine 092642 ( QBG QBG70773 ), along the roadside between 70 and 84 miles (Mindat-Matupi car road), Matupi Township, near the Natma Taung National Park ,alt. 2225 m, N21°36.007' E93°39.313', 22 July 2013 ; Funakoshi et al. 085231 ( QBG QBG61271 ), 14 miles towards Madupi from Mindat , alt. 2355 m, N21°23.894' E93°45.901', 9 Sept. 2011 ; Fujikawa et al. 094892 ( QBG QBG70796 ), c. 10 miles from Mindat between Mindat and Matupi (Mindat-Matupi road), Mindat Township, Natma Taung National Park , alt. c. 1800 m, 1 Sept. 2013 .

Notes — Impatiens striolata is most similar to I. putaoensis but differs in having bright yellow flowers and a glabrous stem. It is also similar to species numbered 56–65 below but can be easily distinguished by its acute to acuminate apex of the upper lateral petals.

Hooker (1905) mentioned that it was found in the Khasia Hills, at 4000–5000 ft altitude, but without any other detail about type specimens. However, Hooker annotated two specimens as I. striolata : Hooker & Thomson 91 (K000694624) and Hooker & Thomson 2026 (K000694625). We select K000694624 as lectotype because it is provided with a clear illustration and a dissected flower, and its locality matches the protologue.