Impatiens siculifer Hook.f.

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 223

16. Impatiens siculifer Hook.f.

Impatiens siculifer Hook.f. (1908) 246; Y.L. Chen et al. (2007) 55, 68; Gogoi & Borah (2013) 146. — Impatiens siculifera Hook.f. in Kress et al. (2003) 170. — Type: Bodinier 2335 (lecto,designated here P P00780759;isolecto E E00313594), China, Environs de Tou-chan Province de Kouy-Tchéou, 2 June 1898.

Terrestrial annual herb, 35–100 cm tall. Stem erect with some long roots on the lower node, 4–5 mm diam, moderately branch- ed, slightly winged on the upper part, pale green, glabrous to remotely pilose with some glandular hairs on the upper part. Leaves spirally arranged. Petiole flat, 5–20 mm long, 1–1.5 mm diam, glabrous, with stipular wings with 3–many glands on each side of petiole base. Lamina 50–97 by 15–35 mm, elliptic to oblanceolate, apex acute to acuminate, base cuneate to attenuate, margin crenate with teeth at the ridge, green, glabrous, with 1–3 of linear stipular glands on each side along the midrib near lamina base; lateral veins 6–9 pairs. Inflorescence axillary to subterminal, erect, 5–10-flowered raceme. Peduncle 17–36 mm long, c. 1 mm diam, pale green, glabrous. Rachis 5–32 mm long, <1 mm diam, green, glabrous. Flowers 10–25 mm long, 17–20 mm deep, asymmetric, yellow with a red spur. Bracts 3–8 by 2–3 mm, ovate to narrowly lanceolate to narrowly elliptic, apex acute and mucronate, base obtuse, margin entire, without glands, green, glabrous, persistent to caducous in fruiting stage. Pedicel 13–16 mm long, <1 mm diam, green, glabrous. Lateral sepals 2, 5–6 by 1–3.5 mm, free,

Map 8 Distribution of Impatiens racemosa DC. (●), I. siculifer var. siculifer Hook.f. (●), I. siculifer var. porphyrea Hook.f. (●) and I. austroyunnanensis S.H.Huang (●).

linear-falcate to obliquely ovate, apex acute to acuminate and mucronate, base cuneate, yellow, glabrous. Lower sepal 7.5–10 mm long, 18–25 mm deep including spur, deeply navicular, apex acuminate to aristate with long awns, up to 5 mm, yellow with green awns, glabrous, distal part gradually narrowing into an upcurved spur, red. Dorsal petal 8–9 by 7–10 mm, elliptic to broadly lanceolate, flat, strongly reflexed backward, apex obtuse to round, base obtuse to truncate, green, glabrous, abaxial midvein simple or with a narrow crest, c. 1 mm high. Lateral united petals 18.5–21 mm long, free, slightly different in size and shape between both sides: the upper petals; the left one 9–10 by 5 mm, triangular to broadly lanceolate to obovate, apex acute to round, base cuneate, yellow; the right one 8–11 by 5 mm, obliquely triangular to broadly lanceolate to elliptic, apex acute to obtuse, base cuneate; the lower petals free; the left one 12–15 by 1–1.5 mm, linear and spiral, apex acute, base without to slightly auricled, c. 1 mm high, yellow, glabrous; the right one 13–13.5 by 1–2 mm, linear and spiral, apex acute to obtuse, base slightly spiral, c. 1 mm high, yellow, glabrous. Stamens: filaments c. 4 mm long; anthers yellow. Ovary 3–4 mm long, c. 1 mm diam, green, glabrous. Fruits 19–25 mm long, 2–3 mm diam, linear, 5-lobed, glabrous: fruiting pedicel up to 20 mm long, straight. Seeds unknown.

Note — Impatiens siculifer is very similar to I. stenantha Hook.f. (1875: 478) but the floral bract of I. stenantha drops before the flower expands. In the Flora of China ( Chen et al. 2007), differences in the shape of the lateral sepals and lower sepal apex are mentioned, but those characters are somewhat confusing. Nevertheless, a more detailed study is necessary to delineate I. stenantha and I. siculifer .