A new species of Impatiens (Balsaminaceae) from Southern Xizang, China with supplementary knowledge on I. leptocarpa Hook. f. Author Tian, Jing 0000-0002-6716-7513 CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China & Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China tianjing@wbgcas.cn Author Yuan, Tao-Hua 0000-0001-5278-3068 CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China & College of Ecological Environment, Tibet University, Lhasa 850000, China & College of Life Sciences, Wuhan University, Wuhan 430072, China 1762402547@qq.com Author Peng, Shuai 0000-0002-8064-920X CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China & Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China pengshuai183@163.com Author Yang, Zhu-Zhu 0000-0002-8519-8348 Hubei Zhongsen Ecological Forestry Co., Ltd., Yichang 443000, China 568711970@qq.com Author Hu, Guang-Wan 0000-0001-7728-7976 CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China & Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China & Hubei Jiangxia Laboratory, Wuhan 430200, China guangwanhu@wbgcas.cn Author Wang, Qing- Feng 0000-0001-9143-8849 CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China & Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China qfwang@wbgcas.cn text Phytotaxa 2024 2024-07-25 661 1 47 62 http://dx.doi.org/10.11646/phytotaxa.661.1.3 journal article 10.11646/phytotaxa.661.1.3 1179-3163 13218290 1. Impatiens lhunzeensis J.Tian, G.W.Hu & Q.F.Wang , sp. nov. ( Figs. 1 & 2 , Fig. 3 : A1–I1) Type: — CHINA . Xizang : Shannan Prefecture , Lhunze County , Zhari Township , evergreen broad-leaved forests along understory streams, 2671 m , 28°35′58″N , 93°24′14″E , 14 July 2022 , J. Tian & C. Zhang TIBET-TJ3 ( holotype : HIB, HIB0209753 ; isotypes : HIB , HIB0209754 , HIB0209755 , HIB0209756 ) . Diagnosis: — Impatiens lhunzeensis is different from I. radiata Hook.f. , I. harae H.Ohba & S.Akiyama , I. drepanophora Hook.f. (1905: 22) , I. principis Hook.f. (1908: 246) , and I. eubotrya Miq. (1860: 397) by a combination of following characters: indumentum present on the stem, leaf blade densely hairy, racemose inflorescence, peduncle hairy in lower parts, reniform dorsal petal, navicular lower sepal, broadly ovate to sub-orbicular upper petals, and triangular oblong lower petals. Description: —Annual, non-succulent herbs, 24–50 cm high; stems erect, robust, branched, densely hairy. Leaves alternate; petiole 0.5–2.5 cm long, densely hairy, with 2 clavate basal glands; leaf blade ovate, 1–8 × 0.8–3.5 cm , densely hairy above and on veins beneath, lateral veins 5–9 pairs, margin crenate, apex acuminate. Inflorescence in upper leaf axils, racemose, 6–26-flowered; peduncle 5–10 (to 15) cm long, lower parts hairy, upper parts glabrous; pedicel 1.4–1.9 cm long; bracts ovate, 0.2–0.3 cm long, persistent, apex glandular slender. Flowers pale-pinkish to white, 1.8–2.1 cm long, small; lateral sepals 2, ovate-lanceolate, 0.2–0.3 cm long, apex long mucronulate; lower sepal navicular, apex rostellate, ca. 0.5× 1.2 cm , gradually tapering into straight 0.6–0.8 cm long spur; dorsal petal reniform, apex rounded, ca. 0.3 × 0.5 cm ; lateral united petals white to pink, 1.6–1.8 cm , 2-lobed; upper petal broadly ovate to sub-orbicular, 0.2–0.3 × 0.2–0.3 cm , lower petal triangular oblong, 1.0–1.2 × 0.5 cm , apex obtuse. Anthers obtuse. Ovary 5-carpellate. Capsule linear, 1.8–2.2 cm . Seeds unknown. Etymology: —The specific epithet “ lhunzeensis ” refers to the type locality, Lhunze County. The Chinese name is given as “̎子凤仙花” (lóng-zǐ-fèng-xiān-huā). Phenology: —Flowering late July to August, fruiting late August to September. Habitats: —Moist roadside ditches on the forest margins in the mountains at an elevation range from 2500 to 2800 m . Distribution: — Impatiens lhunzeensis is only found in Lhunze, Xizang , China . Phylogenetic position:— Phylogenetic analysis shows that the new species is nested within I. sect. Racemosae , along with three closely related species: I. principis , I. eubotrya , and I. drepanophora . The clade consisting of the new species and its close relatives is strongly supported by both maximum likelihood and Bayesian inference phylogenetic trees ( Fig. 4 ).