Impatiens drepanophora Hook.f., Rec. Bot. Surv.

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 : 7-8

Impatiens drepanophora Hook.f., Rec. Bot. Surv. India 4: 17 (1905); Toppin, Bull. Misc. Inform. Kew 10: 364 (1920); Chen, Akiyama & Ohba, Fl. China 12: 69 (2007) ; Ruchisansakun et al., Blumea 63: 228 (2018).

– Type: India, Khasia Hills, 6 vi 1850, altitude 6000 ft, Hooker & Thomson 56 (lectotype K [ K000694682 ]; isolectotypes K [ K000694683 , K000694684 , K000694685 , K000694686 , K000694687 ], L n.v [ L0388881 ], designated by Ruchisansakun et al., 2018). Figure 3D–F .

Distribution. This species occurs in Xiengkhouang and Houaphane Provinces in northern Laos. It was originally described from the Khasia Hills in Northeast India and has also been reported from Nepal, South China and Myanmar ( Ruchisansakun et al., 2018).

Habitat and ecology. Impatiens drepanophora was found growing in evergreen montane forest in moist soil near streams, 900–1800 m altitude, associated with ferns.

Phenology. Flowering from June to November, fruiting December.

Specimens examined. LAOs. Houaphane Province : Viengthong District, Nam Et-Phou Louey National Protected Area, along the road from Ban Phou Vieng to Vieng Thong, 5 vi 2013, Leong-ŠKorniČKová et al. JLS2332 ( E [ E00808193 ], HNL, P, QBG, SING, spirit collection at Pha Tad Ke Botanical Garden) ; Phou Kaew Lom , 21 x 2002, Homsombath & Newman 1418 ( E [ E00171894 , E00171894 ]). Xiengkhouang Province : Khoun District, Phou Sam Soum, valley of primary evergreen forest, 9 ix 2016, K. Souvannakhoummane et al. KS–Bio 0038 ( FOF, HNL) .

From the coloration of the spur, some specimens of Impatiens drepanophora in Laos look very similar to I. longiloba Craib , a Thai endemic species, but it is easily distinguished by having aristate-glandulate tips at the apices of the lateral and lower sepals (versus none). It is also very close to Impatiens ruiliensis S.Akiyama & H.Ohba of China, or even conspecific. More studies are needed to confirm their identities.

Figures

Figure 3. A–C, Impatiens damrongii: A, plant with flower; B, lateral view of bud; C, partial front view of flower. D–F, Impatiens drepanophora: D, plant with flowers; E, raceme and lateral view of flowers; F, oblique view of flowers. G–I, Impatiens kamtilongensis: G, plant with flower; H, front view of flower; I, lateral view of flower. Scale bars: 1 cm. Photographs: A–C, K. Phoutthavong; D–F, K. Souvannakhoummane; G–I, S. Lanorsavanh.