Cassiope fastigiata (Wall.) D. Don subsp. sennikovii D. Maity, subsp. nov. (Ericaceae) is described from Sikkim Himalaya. It differs from the previously known typical Cassiope fastigiata (Wall.) D. Don subsp. fastigiata by its funnel-shaped or narrowly campanulate corolla and larger corolla lobes, sepals, stamens and anther awns. This new taxon is described and illustrated. PCA (Principal Component Analysis) and UPGMA (unweighted pair-group method with arithmetic averages) cluster analysis are used to test the identity of Cassiope taxa found in this region. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.