Impatiens curvipes Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 238-239

38. Impatiens curvipes Hook.f. — Map 14; Plate 3d

Impatiens curvipes Hook.f. (1905) 25, 32; W.J. Kress et al. (2003) 169; non Impatiens curvipes sensu T. Shimizu (1970) 196. — Type: Collett 47 (lecto, designated here K K000694694;isolecto K K000694695), Myanmar, Shan States, Shan Hills, alt. 4000 ft (1219 m), Nov. 1887.

Terrestrial, annual, glabrous herb, 30–40 cm tall. Stem erect, 2–2.5 mm diam, solitary or rarely branched, red to reddish green, glabrous to remotely pilose. Leaves spirally arranged, sometimes decussate at the lower nodes of the stem, mostly congested at apex of stem. Petiole sessile– 9 mm long, c. 1.5 mm diam, pale green, pilose. Lamina 20–80 by 13–30 mm, ovate to elliptic to obovate, apex acute, base cuneate, margin serrate, adaxial green with white base and pilose, abaxial greyish green and remotely pilose, with 2–4 pink hairs on each side of margin near the base, up to 2 mm long; lateral veins 3 or 4 pairs. Flowers solitary, axillary, erect, 17–18 by 18– 12 mm, 13–15 mm deep, pink. Pedicel 20–22 mm long, c. 1 mm diam, cylindrical, green, pilose. Bracts c. 1 by <1 mm, linear, apex acute, base obtuse, margin entire, without glands, green, pilose, persistent. Lateral sepals 2, c. 1 by <0.5 mm, free, linear to ovate, apex acuminate, base cuneate, pale green, glabrous. Lower sepal 5–6 by 3–3.5 mm, 8–10 mm deep, navicular, apex acuminate and mucronate, pink, distal part tapering into an incurved spur, 13–15 mm long. Dorsal petal c. 8 by 13 mm, broadly elliptic, cucullate, apex round, base obtuse to cordate, pink, glabrous, pilose at midrib, abaxial midvein with a keel-shaped crest, 2 mm wide. Lateral united petals 15–17 mm long, free: the upper petals c. 5 by 4 mm, orbicular, apex round to truncate, base cuneate to obtuse, deep pink; the lower petals 10–13 by 7–10 mm, free, obliquely ovate to rhombic, apex obtuse, pink with white and yellow mark at the base. Stamens: filaments 3.5–4 mm long, pink; anthers green to pale pink. Ovary 3.5–4 mm long, <1 mm diam, 5-carpellate, green, pilose. Fruits c. 12 mm long, c. 6 mm diam, fusiform, 5-lobed, green, pilose. Seeds c. 25, ellipsoid, c. 1.5 mm long.

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

Distribution — Endemic to Myanmar (southern Shan State).

Ecology — Growing in shady or open areas in mixed deciduous forest, locally abundant, 1200–1800 m altitude.

Other collections examined. MYANMAR, Shan State, Melville 60 (BM), Taunggyi district, Kalaw Township ,alt. 3500 ft, 25 Nov. 1903 ; Tanaka et al. 080208 ( QBG QBG61265 ), Kalaw Township, Yae Aye Kan , N20°35'41" E96°31'46", alt. c. 1200 m, 26 Nov. 2008 ; Srisanga et al. M1­271 ( QBG QBG80456 ), Pindaya Township, Pin Sein Pin Village , N20°59'01.73" E96°37'56.07", alt. c. 1714 m, 14 Dec. 2014 ; Ruchisansakun et al. 718 (L L2071086, RAF, RANG), Taunggyi district, Thansen cave , N20°49'00.46" E97°20'06.24", alt. 1259 m, 18 Sept. 2015 ; Ruchisansakun et al. 721 (L L2071094, RAF, RANG), Taunggyi district, on the way to Shwephonpwiat , N20°46'12.47" E97°03'31.42", 19 Sept. 2015 ; Ruchisansakun et al. 731 (L L2071117, RAF, RANG), Taunggyi district, Pindaya , N20°58'49.53" E96°37'41.62", alt. 1742–1909 m, 26 Sept. 2015 ; Craddock s.n. (K K000694696), southern Shan States, alt. 4800–5800 ft (1463–1768 m), Oct. 1901 ; Collett 949 (K K000694695), ibid., Nov. 1888 ; Khalil s.n. (K K000694697), Shan State, Taungyi, 1893; Robertson 353 (K), ibid., alt. 5000 ft, 26 June 1911 ; U MG Gale 2 12159 ( RAF966012 , 2 sheets), ibid., 27 Sept. 1970 .

Notes — Impatiens curvipes can be easily distinguished from other taxa by its high keel-shaped crest on the abaxial side of the dorsal petal and small upper lateral petals. It is most similar to I. florulenta but differs in having a flat instead of a cucullate dorsal petal, and strongly decurved, instead of spreading or slightly recurved pedicels at fruiting stage. It usually has a

Map 14 Distribution of Impatiens decurva Ruchis. & S.B.Janssens (●), I. balsamina L. (●), I. curvipes Hook.f. (●) and I. florulenta Hook.f. (●).

white leaf base, which is distinct from other species and also detectable in dried herbarium specimens.

Hooker (1905) published I. curvipes but did not designate a type. He wrote this name on some specimens in Kew. We select Collett 47 (K000694694) as lectotype because its locality matches the prologue and it is a complete specimen with detailed illustrations.