Impatiens tavoyana Benth. ex Hook.f. & Thomson

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 246-247

49. Impatiens tavoyana Benth. ex Hook.f. & Thomson — Fig. 18; Map 17

Impatiens tavoyana Benth.ex Hook.f. & Thomson (1860) 114, 146. — Impatiens tavoyana Wall. in Hook.f. (1904a) 29; Hook.f.(1905) 29. — Impatiens tavagua Benth. in Steudel (1840) 805. — Impatiens tavoyana Benth. in Wall . (1831) 168; Hook.f. (1875) 468; (1905) 34; W.J. Kress et al. (2003) 170. — Type: Wall . Cat . no. 4773 (lecto K K001039869), Myanmar,Tavoy.

Annual herb, 18–23 cm tall. Stem erect, 1.5–2.5 mm diam,moderately branched, green, glabrous. Leaves spirally arranged, decussate only in the lowest node. Petiole 5–15 mm long, <1 mm diam, glabrous. Lamina 21–43 by 11–16 mm, elliptic to ovate, apex acute, base cuneate, margin shallowly serrate, glabrous, with 3 or 4 pairs of long hairs near lamina base, 1–2 mm long; lateral veins 5 or 6 pairs. Inflorescence axillary, erect, 6- or 7-flowered raceme. Peduncle 10–17 mm long, <0.5 mm diam, glabrous. Rachis 4–7 mm long, glabrous. Flowers 8–9 mm long, c. 3 mm deep. Bracts c. 1 by 0.5 mm, ovate, apex acute to acuminate, base obtuse to cuneate, margin entire, glabrous, persistent. Pedicel c. 2.5 mm long, <1 mm, glabrous. Lateral sepals 2, c. 2 by 1.5 mm, free, ovate, apex acuminate and mucronate, base obtuse, glabrous. Lower sepal c. 3 mm long, c. 1.5 mm deep, navicular, apex acute and mucronate, distal part rapidly constricted to a globose spur, c. 0.8 mm long. Dorsal petal unknown. Lateral united petals c. 6.5 mm long, free: the upper petals 2.5–3 mm long, completely reduced as a stipe of lower petals; the lower petals 3.5–4 by 2.5–3 mm, free, broadly ovate, apex truncate, base without auricle. Stamens unknown. Ovary unknown. Fruits 3.5 mm long, 1.5–2 mm diam, short fusiform, glabrous. Seeds 2 or 3, c. 1.5 mm long.

Phenology — Unknown.

Distribution — Endemic to Myanmar (Tanintharyi Region).

Ecology — Unknown.

Notes — Impatiens tavoyana is morphologically very similar to I. circaeoides , I. rangoonensis and I. peguana , but differs in having a globose spur.

The specimen Wall . Cat . no. 4773 (K001039869) is designated as lectotype here as it is the only specimen we found.