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

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 244

47. Impatiens circaeoides Wall. ex Hook.f. & Thomson — Map 16; Plate 4a

Impatiens circaeoides Wall. ex Hook.f. & Thomson (1860) 114, 130; Hook.f. (1875) 453; (1905) 29, 34; W.J. Kress et al. (2003) 169. — Impatiens circaeoides Wall. (1831) 168,nom.nud.,non Impatiens circaeoides Turcz.(1863) 594. — Type: Wall . Cat . no. 4772B (lecto,designated here K K001039868), Myanmar ( Burma), Yangon (Rangoon), 16 Aug. 1826.

Impatiens lineata Turcz.(1859) 271. — Type: Lobb 391 (holo KW001000649*), Myanmar, Mon State, Mawlamyine (Moulmain).

Impatiens brandisii Hook.f. (1905) 29; W.J. Kress et al. (2003) 169, syn. nov. — Type: Brandis s.n. (lecto, designated here K K000694710; isolecto L L0388789), Myanmar, Tenasserim, at Thoungyeen.

Terrestrial, annual, glabrous herb, 25–35 cm tall. Stem erect, 2–5 mm diam, laxly branched, green. Leaves spirally arranged but decussate at the lowest node. Petiole 8–22 mm long, up to 1 mm diam, cylindrical, green, glabrous. Lamina 30–70 by 17–34 mm, ovate, apex acute to acuminate, base attenuate, margin shallowly crenate with many long hairs near the base, adaxial green, abaxial greyish green, glabrous, without glands; lateral veins 4–6 pairs. Inflorescence subterminal, in 12–14-flowered racemes. Peduncle 30–45 mm long, c. 1 mm diam, cylindrical, purple, glabrous. Flowers c. 20 by 13 mm, c. 8 mm deep, yellow. Pedicel 8–15 mm long, <1 mm diam, green, glabrous. Bracts 1.5–2 by c. 0.5 mm, lanceolate, apex acute, base cuneate, margin entire, green, glabrous, persistent. Lateral sepals 2, 1.5–2.5 by c. 0.5 mm, free, linear to lanceolate, curved, apex acute to obtuse, base cuneate, green, glabrous. Lower sepal 5–7 by 2–3 mm, 1.5–22 mm deep, navicular, apex acute and mucronate, base obtuse, yellow, quite pellucid, with red reticulate lines, green apex, distal part abruptly constricted into a narrow incurved spur, 5.5–7 mm long, yellow with green tip. Dorsal petal c. 4.5 by 1.5–2 mm, ovate, cucullate, apex acute to obtuse, base cordate to round, yellow, glabrous, abaxial midvein simple. Lateral united petals 16–17 mm long, free: the upper petals 1.5–2 by 0.5–1 mm, falcate, apex acute, base stipitate, yellow; the lower petals 10–12 by 6.5–7 mm, free, obliquely ovate, apex round, base cuneate, yellow, glabrous. Stamens: filaments 2.5–3 mm long, white; anthers pale yellow to white. Ovary 2.5–3 mm long, c. 1 mm diam, 5-carpellate, green, glabrous. Fruits 8–9 mm long, 2–3 mm diam, fusiform, 5-lobed, green, glabrous. Seeds 4–6, ellipsoid, c. 1.5 mm long, brown.

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

Distribution — Myanmar (Ayeyarwady Division, Bago Division, Chin State, Kayin State, Magway Division, Mon State, Rakhine State, Yangon Division), Thailand (Kanchanaburi Province).

Ecology — Growing in shady areas along roadsides in cloud forests or mixed deciduous forests, abundant at localities, 60–900 m altitude.

Other collections examined. MYANMAR, Wall . Cat . no. 4772A (para K K001039867),Pyay (Prome); Ayeyarwady Region, Allan s.n. (E E00753094), Hinthada (Henzada) district, Kyangin Reserve, 22 Sept. 1908; Lace 3115 (K K000694712,4 sheets),ibid., May 1908; Bago division, Rogers 5 (K 2 sheets), Tharrawaddy district,Myaung Chaung,west slope Pegu Yoma, 24 Nov.1911; Rogers s.n. (E E00753095),Tharrawaddy district, Thapau Reserve,alt. 500 ft, 28 Oct. 1912; Lacei 5 400 (K 2 sheets), Toungoo, Kyunpadaung Range near Kyaukkyi, 11 Aug.1911; Lace 5034 (K),Toungoo district,Vujunpadaung Range,near Kyaukkyi, 11 Aug.1911; Lace 5033 (E E00753096,K), Bago division,Toungoo district,donyan chaung,pasrsura reserve, 19 Dec. 1909; Kurz 1872 (K), Pegu Yomah, east and west slope, 7 Jan. 1971; Chin State, Ling Shein Man & Ha Shein Aung 087435 (QBG QBG61273),Ma Kyauk Ah Village area, Kanpetlet Township, alt. c. 5000 ft, 24 June 2011; Fujikawa, Srisanga, Maknoi, Tin Mya Soe, Ling Shein Man, Tun Tin & Law Shine 094311 (QBG QBG70790), along foot path and unpaved new car road between Kanpetlet and Yelong Pan village, Kanpetlet Township, Natma Taung National Park, alt. 1260–1435 m, N21°13'07.9" E94°03'46.4", 23 Aug. 2013.

Notes — Hooker cited Wall . Cat . no. 4772 in the protologue of I. circaeoides . However, this number consists of two specimens; Wall . Cat . no. 4772A (K001039867) and Wall . Cat . no. 4772B (K001039868). We select the Wall . Cat . no. 4772B (K001039868) as the lectotype because it has an illustration by Hooker.

This species is similar to I. tavoyana but differs in having a linear incurved spur vs a globose spur.

Impatiens circaeoides Turcz. (1863: 594) is an illegitimate name and was synonymized under I. goughii Wight (1840: 160) by Hooker (1875).

We found two sheets of Brandis s.n. with the name I. brandisii with matching information to the protologue ( Hooker 1905). We select Brandis s.n. (K000694710) as lectotype because it also has an illustration.