Impatiens margaritifera var. humilis Y.L.Chen

Smets, E. F. & Janssens, S. B., 2018, Balsaminaceae of Myanmar, Blumea 63 (3), pp. 199-267 : 221

13. Impatiens margaritifera var. humilis Y.L.Chen — Map 7

Impatiens margaritifera var. humilis Y.L. Chen (1978) 45;Y.L. Chen et al. (2007) 79. — Type: Yu 12841 (holo PE PE00039573*; iso HUH HUH00230517*, PE PE00039571*, PE PE00039572*, PE PE00039574*), China, Sichuan, Daocheng, Mowu, alt. 1128–1219 m.

Annual glabrous herb, 10–26 cm tall. Stem erect, unbranched to sparsely branched, glabrous. Leaves spirally arranged and decussate at the lower nodes. Petiole 10–20 mm long, glabrous. Lamina 48–57 by 18–23 mm, ovate, apex acute to acuminate, base obtuse to cuneate, margin distinctly crenate with teeth, glabrous, with or without 1 pair of glands at the base of the lamina; lateral veins 4 or 5 pairs. Inflorescence axillary, erect, 2–6-flowered subumbellate raceme. Peduncle 20–30 mm long, glabrous. Rachise 1–4 mm long, glabrous. Flowers 12–14 mm long, 3–5 mm deep, pink to pale purple to pale greenish yellow. Bracts c. 4 by 1 mm, linear, apex acute, base cuneate, margin entire, persistent. Pedicel 5–6 mm long. Lateral sepals 2, c. 3 by 2 mm, ovate, apex acute, base obtuse. Lower sepal c. 7 mm long, c. 3 mm deep, navicular, without spur. Dorsal petal c. 6 by 5 mm, ovate, cucullate, apex obtuse, base obtuse, abaxial midvein simple or with a narrow crest. Lateral united petals c. 15 mm long, free: the upper petals c. 8 mm long, ovate, apex obtuse to acute; the lower petals c. 8 mm long, free, narrowly ovate, apex obtuse to acute. Stamens unknown. Ovary unknown. Fruits unknown. Seeds unknown.

Phenology — Flowering: July to August.

Distribution — Myanmar (Kachin State), China (Sichuan Province, Yunnan Province).

Ecology — Growing in evergreen forest, 2000–4000 m altitude.

Other collections examined. CHINA, Yu 22301 (para PE PE00078824*), Mekong-Salwin Divide, Sila , alt. 4000 m, 11 Aug. 1938 . – MYANMAR, Kachin State, Kingdon­Ward 7164 (K), Valley of Di Chu , alt. 7000 ft, 22 July 1926 .

Note — Impatiens margaritifera var. humilis is similar to var. margaritifera , but differs in having a shorter stem, a shorter rachis and fewer flowers in each inflorescence. It is also similar to I. tenerrima Y.L. Chen (1978: 51) but differs in having a 2–6-flowered raceme (vs a solitary flower), lateral united petals of c. 15 mm long (vs 25–30 mm), a taller stem and longer leaves.