Impatiens psittacina Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 217-219

8. Impatiens psittacina Hook.f. — Map 5; Plate 1f

Impatiens psittacina Hook.f. (1901) t. 7809; (1905) 30; Craib (1926b) 213; T. Shimizu (1970) 189; W.J. Kress et al. (2003) 169. — Type: Hildebrand 5 (holo K K000694762), Myanmar, 5 Oct. 1900.

Lithophytic, annual, glabrous herb, 30–100 cm tall. Stem erect, 3–22 mm diam, solitary moderately branched, angular, purple. Leaves spirally arranged. Petiole 35–80 mm long, 1.5–2 mm diam, green to purple. Lamina 40–115 by 27–75 mm, ovate, apex acute to acuminate, base round to attenuate, margin

Fig. 11 Impatiens micromeris Hook.f. a. Habit; b. front view of flower; c. lateral view of flowers; d. upper lateral sepals; e. lower lateral sepals; f. lower sepals; g. dorsal petal; h. lateral united petals; i. pedicel and ovary; j. fruit; k. seed. — Drawn by Saroj Ruchisansakun.

serrate, adaxial green, abaxial pale green, with a short clavate gland on each side of margin near the base; lateral veins 9 or 10 pairs. Inflorescence axillary, pendulous, 2-flowered raceme. Peduncle 1–2 mm long, c. 1 mm diam, green. Rachis c. 1 mm long, <1 mm diam. Flowers 33–37 by 27–34 mm, 37–45 mm deep, pink. Pedicel 36–37 mm long, c. 1 mm diam, green. Bracts 3–4 by 1 mm, linear to lanceolate, apex acute, base cuneate, margin entire, without gland, green, persistent. Lateral sepals 2, 10–13 by 9–11 mm, free, elliptic to obovate, apex round and mucronate, base obtuse, white to green to dark pink. Lower sepal 15–16 by 17–18 mm, 25–27 mm deep, deeply bucciniform, apex acuminate and mucronate, white, and red on basal part, with a yellow mark inside, distal part abruptly constricted into a short hook-like spur, 5–6 mm long, green. Dorsal petal 15–16 by 17–18 mm, orbicular, flat, apex round and slightly emarginate, base obtuse to round, white to pale pink, abaxial midvein with a wide crescent-shaped crest at the base, 4–5 mm wide, green to pink. Lateral united petals 42–45 mm long, connate: the upper pair 12–13 by 14–16 mm, orbicular to broadly ovate, apex round, base cuneate, white with a pale pink margin; the lower pair 33–35 by 10–11 mm, connate, broadly oblong, apex round to slightly emarginate, pink, white at the base with a yellow mark. Stamens: filaments 9–10 mm long, white; anthers white. Ovary 9–10 mm long, c. 1 mm diam, 4-carpellate, green. Fruits 20–22 mm long, 2.5–3 mm diam, clavate, 4-lobed, green. Seeds c. 6–8, ellipsoid to brick shaped with papillae, c. 2 mm long.

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

Distribution — North-eastern Myanmar (Shan State), northern Thailand.

Ecology — Growing on limestone with little organic matter in shady areas in mixed deciduous forest, 1000–1100 m altitude.

Other collections examined. MYANMAR, Shan State, Ruchisansakun et al. 727 (L L2071111, MAND, RAF), Taunggyi District, Lwa Taw village , N20°40'44.35" E97°10'31.93", 22 Sept. 2015 .

Note — Impatiens psittacina is well-known to plant collectors and horticulturists. Populations in Myanmar have mainly red spurs, whereas populations in Thailand are characterized by green spurs. The species is pollinated by bumblebees ( Ruchisansakun et al. 2016), which have the pollen deposited on their thorax as they enter the flower, while their wings are spread.