Impatiens andersonii Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 254-255

62. Impatiens andersonii Hook.f. — Map 21; Plate 4e

Impatiens andersonii Hook.f.(1905) 27,33; W.J. Kress et al.(2003) 169. — Type: Anderson s.n. (lecto, designated here K K000694627), Myanmar, Shan State, Hoetone , 1 Sept. 1868.

Impatiens garrettii Craib (1926a) 160, syn. nov. — Type: Garrett 94 (lecto, designated here K K000675566; isolecto BKF005985, E E00753953, K K000675566), Thailand, Chom Thong , Doi Angka , Pha Ngaem , Doi Inthanon National Park, Doi Angka, 1300–1675 m.

Terrestrial, annual herb, 22–40 cm tall. Stem erect, 3–8 mm diam, solitary to richly branched, angular, pale green, sometimes with purple dots, pilose towards apex, glabrous on the lower part. Leaves spirally arranged. Petiole 40–45 mm long, or much shorter in leaves subtending floral buds, measuring 1–2 mm long, 1–2 mm diam, angular, green to purple, glabrous. Lamina 50–100 by 20–45 mm, ovate to elliptic, papyraceous, apex acute to acuminate, base obtuse to attenuate, margin crenate, adaxial green and pilose, abaxial pale green and remotely pilose, with a short clavate gland on each side of lamina base; lateral veins 11–14 pairs. Inflorescence axillary, pendulous, 1- or 2-flowered racemes. Peduncle 12–15 mm long, <1 mm diam, cylindrical, green, pilose. Rachis <1 mm long, <1 mm diam. Flowers 20–25 mm long, 15–17 mm wide, 20–23 mm deep, pink with pale pink and yellow mark at lower sepal. Pedicel 3–4 mm long, <1 mm diam, white to pale green, glabrous. Bracts up to 2 by <1 mm, apex acute, base cuneate, margin entire, without glands, white to pale green, glabrous, persistent. Lateral sepals 2, 5–6 by 2–3 mm, free, obliquely ovate to falcate, apex acuminate and mucronate, base obtuse, white to green, semipellucid, with green apex, glabrous. Lower sepal 11–12 by 5–7 mm, 9–10 mm deep, bucciniform, apex acuminate, pale pink with darker pink lines and yellow mark adaxially, distal part gradually constricted into an incurved spur, 14–15 mm long, pale pink. Dorsal petal 9–10 by 5–6 mm, ovate, cucullate, apex acute and mucronate, base truncate, pink, glabrous, abaxial midvein with a slightly crescent-shaped or obtuse crest, c. 0.5 mm wide, white. Lateral united petals 18–19 mm long, free: the upper petals 6–7 by 5–6 mm, broadly obovate, apex truncate, base cuneate, pink; the lower petals 12–14 by 8–9 mm, free, ovate to elliptic, apex obtuse, pink, with yellow auricle at the base. Stamens: filaments 3–4 mm long, white to pale pink; anthers white. Ovary c. 3 mm long, c. 1 mm diam, 5-carpellate, white, glabrous. Fruits c. 9 mm long, c. 4 mm diam, fusiform, 5-lobed, white to pale green, semipellucid, glabrous. Seeds c. 5–7, ellipsoid, c. 2 mm long, remotely pilose.

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

Distribution — Myanmar (Shan State), northern Thailand.

Ecology — Growing in shady areas in mixed deciduous forest along roadsides, 1600–1700 m altitude.

Other collections examined. MYANMAR, Shan State, Ruchisansakun et al. 733 (L L2071122, MAND, RAF), Taunggyi District, Pindaya , Inzen village , N20°58'53.31" E96°38'03.14", 26 Sept. 2015 .

Notes — Impatiens garrettii is similar to I. andersonii . No characters can be found that distinguish the two species and as a result they are synonymized here. The name I. andersonii Hook.f. subsp. garrettii (Craib) T. Shimizu was used to annotate some specimens but was never officially published. Hooker (1905) mentioned only the locality of I. andersonii but did not designate a type specimen. However, we found that only one specimen, Anderson s.n. (K000694627), matches the protologue ( Hooker 1905). Hence, we designate this specimen as the lectotype. Regarding the unclear locality of this specimen, Hotone or Floetone, Yunan (Yunnan), we confirmed from Anderson’s book that the lectotype was collected in Hoetone, near Bhamo, Myanmar ( Anderson 1871: 382).

For I. garrettii , we found four sheets of Garrett 94 and select K000675566 as lectotype because it is the most complete specimen with a dissected flower.