Chamaegastrodia reiekensis: A new holomycotrophic orchid from Mizoram, Northeast India

Chamaegastrodia reiekensis, a holomycotrophic orchid from Northeast India (Mizoram) is described and illustrated as a new species. It is compared with its closely allied species Chamaegastrodia guidongensis, which although similar in morphology and mycoheterotrophic nature can be distinguished by the presence of slender rhizome, compact sheathing scales, floral bracts equalling or exceeding the ovary in length, larger sepals and petals with more dilated hypochile and distinctly sinuate mesochile margin. A key to species for the genus Chamaegastrodia is also incorporated. The conservation status of the newly described species is also provisionally assessed here as Critically Endangered (CR) according to International Union for Conservation of Nature (IUCN) Red List Categories and Criteria.