Impatiens napoensis Y.L.Chen, Acta Phytotax. Sin. 38, 6: 557, f. 1 (2000); Chen, Akiyama & Ohba, Fl. China 12: 84 (2007); Nguyen, Tong & Xia, J. Trop. Subtrop. Bot. 26, 5: 546 (2018).

– Type: China, Guangxi, Napo, Depu Regio Conservation Nature, 1300 m altitude, 3 xi 1998, H. N. Qin et al. 1939 (lectotype PE! [PE01879289]; isolectotype PE! [PE01879290], designated by Nguyen et al., 2018). Figure 4D–F .

Distribution. This species has been found in Xiengkhouang Province, northern Laos. The original description was based on type material collected in Guangxi, China (Chen, 2000), and the species has also been reported from Vietnam (Nguyen et al., 2018).

Habitat and ecology. Impatiens napoensis was found growing in moist soil in primary evergreen forest, on a mountain slope in a valley at 1800 m altitude on Phou Sam Soum near the border between Khoun and Mok Districts.

Phenology. Flowering is from August to November.

Specimen examined. LAOs. Xiengkhouang Province: Khoun District, Phou Sam Soum, valley of primary evergreen forest, 9 ix 2016, K. Souvannakhoummane et al. KS–Bio 0040 (FOF, HNL) .

Impatiens napoensis is similar to I. purpurata Tardieu but differs in forming larger plants; the laminas are ovate-lanceolate, 5–10 × 3–5 cm (versus ovate to orbiculate, 2 × 2 cm), and the lateral sepals are lanceolate to ovate, 8–12 × 4–6 mm, with 5–7 veins (versus ovate to orbiculate, 10 × 5 mm, with 3–5 veins).