Impatiens citrina Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 228

20. Impatiens citrina Hook.f. — Map 9

Impatiens citrina Hook.f. (1905) 17, 22. — Type: Griffith 1235 (lecto, designated here K K000694584), India, Arunachal Pradesh, Mishmi Hills .

Map 9 Distribution of Impatiens prainii Hook.f. (●), I. bracteolata Hook.f. (●), I. citrina Hook.f. (●) and I. drepanophora Hook.f. (●).

Terrestrial, annual herb, up to 50 cm tall. Stem erect, simple to laxly branched, glabrous. Leaves spirally arranged. Petiole 7–15 mm long, glabrous. Lamina 350–400 by 80–85 mm, ovate to elliptic, apex acute to acuminate, base obtuse to cuneate, margin crenate, adaxial green, abaxial pale green, glabrous, without stipular glands; lateral veins 7 or 8 pairs. Inflorescence axillary to subterminal, erect, 10–15-flowered raceme. Peduncle 70–75 mm long, green, glabrous. Rachis 55–80 mm long. Flowers c. 25 mm long, c. 50 mm deep, asymmetric, yellow. Bracts ovate, caducous. Pedicel 18–20 mm long, slender, glabrous. Lateral sepals 2, c. 5 by 4 mm, free, obliquely elliptic to ovate, apex acute to obtuse and mucronate, base obtuse, green, glabrous. Lower sepal 8–10 mm long, 18–20 mm deep, deeply navicular, apex acuminate and aristate with long awn, yellow, glabrous, constricted into an upcurved spur, sometimes involute, 5–15 mm long, minutely bifid. Dorsal petal 9–17 by 5 mm, ovate to orbicular, flat, strongly reflexed backward, apex obtuse to round, base cuneate to obtuse, abaxial midvein simple or with a narrow crest, glabrous. Lateral united petals free, asymmetric: the left upper petal 8–10 by 3–4 mm, curved spatulate, apex acute, base stipitate; the right upper petal c. 9 by 5 mm, obovate to elliptic, apex acuminate, base obtuse, margin entire; the lower petals free; the left lower petal 14–22 by 2–5 mm, oblong to dolabriform, apex obtuse, glabrous; the right lower petal c. 15 by 3 mm, lanceolate, apex acute. Stamens: filaments c. 4 mm long. Ovary glabrous. Fruits 9–13 mm long, 1–2 mm diam, linear, glabrous.

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

Distribution — Myanmar (Kachin State), India (Arunachal Pradesh State).

Ecology — Growing in gullies near streams, 1100–1200 m altitude.

Other collections examined. MYANMAR, Kachin State, Armstrong et al. 1326 (NY NY02649175*), Putao District, Naungmung Township , N27°40'51.3" E97°53'59.3", alt. 1182 m, 6 Nov. 2015 .

Notes — Impatiens citrina differs from I. pseudocitrina Hareesh ( Hareesh et al. 2017: 231) in having a 10–15-flowered inflorescence vs 2- or 3-flowered inflorescences, and in lacking stipular glands.

Hooker (1905) did not designate a type specimen of this species in the protologue. We select the specimen Griffith 1235 (K000694584) as lectotype because it is the only specimen written as I. citrina with an illustration by Hooker.