A new species, Isodon purpurescence Sunil, Naveen Kumar & Ratheesh, from Ernakulam (Western Ghats), India is described and illustrated. Its diagnostic characters are discussed and comments made on differences between this and related species.
Chum-Lei Xiang and En-De Liu. 2012. A new species of Isodon (Lamiaceae, Nepetoideae) from Yunnan Province, South-west China. Syst. Bot. 37 (3): 811–817.
Ya-Ping Chen, Guo-Xiong Hu and Chun–Lei Xiang. 2014. Isodon delavayi (Ocimae, Neptoideae, Lamiaceae): a new species from Yunnan Province, South-west China. Phytotaxa 156 (5): 291– 297.
Zhong, J.S., Li, J., Li, L., Conran, J.H. and Li, H.W. 2010. Phylogeny of Isodon (Schard. ex Benth.) Spach (Lamiaceae) and related genera inferred from nuclear ribosomal ITS, trnL–trnF region, and rps16 intron sequences and morphology. Syst. Bot. 35(1): 207–219.