215 Gardens’ Bulletin Singapore 73(1): 215–220. 2021 doi: 10.26492/gbs73(1).2021-11 Clarifcation of the taxonomic identity, typifcation and nomenclature of Impatiens benthamii (Balsaminaceae) R. Gogoi 1* , B.B.T. Tham 2 , N. Sherpa 1 , J. Dihingia 3 & S. Borah 4 1 Botanical Survey of India, Sikkim Himalayan Regional Centre, P.O. Rajbhawan, Gangtok–737103, Sikkim, India * rajibdzuko@gmail.com 2 Botanical Survey of India, Eastern Regional Centre, Shillong – 793003, Meghalaya, India 3 Dakshin Kamrup Bidyapith High School, Mirza – 781125, Assam, India 4 Department of Botany, Gauhati University, Guwahati – 781014, Assam, India ABSTRACT. Impatiens benthamii Steenis (Balsaminaceae) is re-collected from the type locality, Khasi Hills, Meghalaya, India, almost 60 years since it was last collected. The history and nomenclatural complexity of this little-known endemic species is discussed. A clarifcation of the distributional range of the species is given due to previous erroneous reports. To facilitate its proper identifcation, a detailed description based on live materials and colour photographs is provided. The characters of Impatiens benthamii are compared to those of closely related species. A lectotype is designated. Keywords. Distribution, endemic, Khasi Hills, lectotype Introduction The Indian species Impatiens radicans Benth. ex Hook.f & Thomson frst appeared in Wallich (1832) but this name was not validly published. It was later validly published in Hooker & Thomson (1859). In the same publication they also published Impatiens salicifolia Hook.f. & Thomson which was later synonymised with I. radicans (Hooker, 1905). However, the name Impatiens radicans Benth. ex Hook.f. & Thomson is a later homonym of I. radicans Zoll. & Moritzi (Moritzi, 1846). Impatiens radicans Zoll. & Moritzi is now treated as a synonym of I. cyclocoma Miq. Likewise, Impatiens salicifolia Hook.f. & Thomson is a later homonym of I. salicifolia Turcz. (Turczaninow, 1859). Whilst studying the Impatiens species of Java, Van Steenis (1948) was the frst to notice that the Indian species did not have a legitimate name and named it I. benthamii Steenis in honour of George Bentham. Impatiens benthamii Steenis is a very little-known endemic species confned to the Khasi and Jaintia Hills in the Indian state of Meghalaya. In the Plants of the World Online portal (POWO, 2019), publications by Sarmah & Borthakur (2009)