Range extension of lesser-known orchids to the Nilgiris of Tamil Nadu, India

: The present paper records the extended distribution of orchids, viz., Oberonia chandrasekharanii V.J.Nair, V.S.Ramach. & R.Ansari, Peristylus plantagineus (Lindl.) Lindl., Porpax exilis (Hook.f.) Schuit., Y.P.Ng & H.A.Pedersen, and P. jerdoniana (Wight) Rolfe, to the Nilgiris of Tamil Nadu

For Focus, Scope, Aims, and Policies, visit https://threatenedtaxa.org/index.php/JoTT/aims_scopeFor Article Submission Guidelines, visit https://threatenedtaxa.org/index.php/JoTT/about/submissionsFor Policies against Scientific Misconduct, visit https://threatenedtaxa.org/index.php/JoTT/policies_variousOrchids, one of the highly evolved or advanced flowering groups in the Plant Kingdom are known for their shape, structure, colour and everlasting flowers.The diversity of orchids is extensive; they are distributed all the way from tropics to alpine meadows with varied habits for their survival like epiphytes, lithophytes, saprophytes, and terrestrials."The Orchids of India" accounts with 1,256 taxa belonging to 155 genera with 307 endemic species; while the Western Ghats is represented by 305 species under 75 genera among which 128 species are endemic to the region; whereas from Tamil Nadu state, 215 species under 62 genera are documented of which 92 species are endemic (Singh et al. 2019).From the Nilgiris district of Tamil Nadu 113 species were reported by Sharma et al. (1977), later Joseph (1982) documented 116 species under 49 genera.
Recently, Jeevith et al. (2019) recorded 37 species belonging to 23 genera from the shola and grasslands of the Nilgiris.
Naturally, plants distribute or migrate through seed dispersal by various kinds of agents, viz., wind, water, insects, birds, and animals.Sometimes, their dispersion is enhanced through environmental disasters like cyclone, flood, torrential rain, causing translocation to an extended distance or range extension.Thus, previously distributed floral elements grow with the new associations.The regional flora workers should significantly document the new invasion of native or exotic species.It facilitates to compare the floristic assessment of an area on different time periods.
Although the flora handbook and pictorial guide of the Nilgiris is available, its flora is being continuously updated by new distribution records (Kiruthika et al. 2018;Kaliamoorthy & Saravanan 2019).The present paper highlights the range extension of four lesser-known orchids from the Nilgiris district of Tamil Nadu.Each species is supplemented with description, photographs, and other relevant details for easy identification (Image 1).

Study area
The Nilgiris district of Tamil Nadu is geo-positioned between 11.2-11.61 0N latitude and 76.5-76.91 0 E longitude and ranging in altitude between 300 to 2,637 m.It lies phytogeographically in the Western Ghats covering total forest cover with 1,731.01km 2 of which 466.72 km 2 , 629.85 km 2 , and 634.44 km 2 area with dense forest, moderate dense forest, and open forest respectively (India State Forest Report 2019).The hilly district is surrounded by Karnataka in the north, Kerala in the west, Coimbatore in the south, and Erode in the east.

Methods
After studying the indigenous medicinal plants in the Nilgiris district of Tamil Nadu (2016Nadu ( -2018)), the authors collected a few species of orchids.The survey was supported with recording the field data, geo position and photograph of the species.The orchids were identified and studied using national and regional flora (Ansari & Balakrishnan 1990;Kumar & Manilal 1994;Fischer 1928Fischer , 2004;;Misra 2007;Singh et al. 2019) and specimen examined in CAL, FRC, MH, and virtual herbarium of K.The voucher specimens are deposited at PSGR Krishnammal College for Women, Coimbatore, Tamil Nadu.
Flowering & Fruiting: January-May Habitat: Porpax exilis is found in colonies on the host of Litsea sp.; it is associated with Pinalia mysorensis (Lindl.)Kuntze Lindl.and Bulbophyllum sp. in the tropical evergreen forests.