Impatiens rubrostriata Hook.f.

Souvannakhoummane, K., Newman, M. F., Lanorsavanh, S. & Suksathan, P., 2021, Impatiens rostrata (Balsaminaceae), a new species from Khammouane Province, Laos, and nine new records, Edinburgh Journal of Botany 78 (362), pp. 1-15 : 13

Impatiens rubrostriata Hook.f. , Hooker’s Icon. Pl. 30: pl. 2954 (1911); Chen, Akiyama & Ohba, Fl. China 12: 65 (2007).

– Type: China, Yunnan, forests of Tchoung-chan , 16 viii 1909, Ducloux 3606 (lectotype P [ P00492336 ], designated here; isolectotypes P [ P00492337 , P00492338 ]). Figure 5A–C .

Distribution. This species has been found on Phou San in Xiengkhouang Province, northern Laos. The original description was based on material from Guangxi, China ( Hooker, 1911).

Habitat and ecology. Impatiens rubrostriata was found growing by streams in moist sandy soil in primary evergreen forest, in mountain valleys at 1800–2200 m altitude on Phou San and Phou Sam Soum.

Phenology. Flowering from August to November, fruiting estimated to take place from October to December.

Specimens examined. LAOs. Xiengkhouang Province : Pek District, O-An village, Phou San, in primary evergreen forest, 7 vii 2016, Souvannakhoummane et al. KS–Bio 0029 ( FOF, HNL) ; Khoun District , Phou Sam Soum, valley in primary evergreen forest, 9 ix 2016, Souvannakhoummane et al. KS–Bio 0036 (FOF, HNL); Champasak Province, Paksong District , Dong Hua Sao National Protected Area, 11 xii 2018, Tagane, S., Nagahama, A., Souladeth, P., Pisuttimarn, P. L2100 ( FOF) ; Bolikhamxai Province, Khamkeut District , Phou Chom Voy Provincial Protected Area , 6 x 2020, Lanorsavanh, S., Lamxay, V. SL 2009 (Biology herbarium, Faculty of Natural Science, National University of Laos) .

Impatiens rubrostriata is similar to I. duclouxii Hook. f. but differs in having white flowers with red stripes on the lateral united petals (versus entirely yellow flowers), and the lateral sepals being larger and white with a red spot or entirely red (versus lateral sepals smaller and greenish to yellow).

Figures

Figure 5. A–C, Impatiens rubrostriata: A, plant with flowers; B, front view of flower; C, lateral view of flower. D–F, Impatiens lobbiana: D, plant with flower; E, front view of flower; F, lateral view of flower. G–I, Impatiens tigrina, red form: G, plant with flower; H, front view of flower; I, lateral view of flower. J, Impatiens tigrina, red-purple form, front view of flower. K and L, Impatiens tigrina, yellow form: K, front view of flower; L, lateral view of flower. Scale bars: 1 cm. Photographs: A–F, K. Souvannakhoummane; G–J, S. Lanorsavanh; K and L, K. Phoutthavong.