Extended distribution, IUCN redlist assessment and in vitro propagation of endemic orchid Crepidium manikathilum (Orchidaceae) from Southern Western Ghats, India

Crepidium manikathilum is an endemic orchid species recently discovered in the Southern Western Ghats, known only from its type locality with a single population. To date, this endemic species remains largely under-explored with no conservation efforts. The main objective of this study is to identify a new geographical distribution, assess threat status as per IUCN, revise taxonomic treatment, and produce multiple seedlings of C. manikathilum through in vitro. The field survey was conducted in the Southern Western Ghats region during the period of 2020 to 2024. A new distributional record was documented with two new subpopulations at Kodaikanal and Ooty in Tamil Nadu, India. The extent of occurrence and area of occupancy were calculated as 3979.244 km2 and 8 km2, respectively. The findings indicate that this species is classified in the Critically Endangered (CR) category. Further, mature pods were collected and tested for asymbiotic seed germination in three basal media. Mitra medium was effective for stage I, and stages II and III were high in MS medium. Asymbiotic seed germination was most successful on B5 medium with 84%, followed by 48% in Mitra medium after two weeks. The in vitro grown explants produced 16 shoots with the combination of 1.5 mg L−1 meta-Topolin with 0.5 mg L−1 IAA. Well-developed plantlets were subsequently acclimatised with a 56% survival rate. The study provides comprehensive details about C. manikathilum for further conservation and assessment.