Studies on <Heliotropium rottleri> Lehm. (Heliotropiaceae) – a threatened endemic plant of Tamil Nadu, India

Heliotropium rottleri Lehm. (Heliotropiaceae; previously Boraginaceae) is endemic to Coimbatore region. Its taxonomic status is ambiguous and unresolved because of mistaken identity of H. marifolium J. Koenig ex Retz. and H. scabrum Retz. by later botanists. So far, no efforts have been taken to assess its distribution, population size, and conservation. While working on Heliotropium L. genus in Tamil Nadu, we have collected it from three localities in the erstwhile undivided Coimbatore district (two in Udumalpet taluk, one in Palladam taluk) in January 2021 and identified with Madras Herbarium, Botanical Survey of India Southern Regional Centre. Our study indicates that it is now Critically Endangered as the habitats are very rapidly altered and changing due to real estate business. Unless urgent actions are taken, certainly this species will disappear. Therefore, it is suggested to take immediate action to conserve this species in its natural habitat.