Notes on the taxonomy and distribution of two rare Thelypteris (Thelypteridaceae) species from Arunachal Pradesh, India, T. repanda and T. birii

Abstract

Based on recent collections, the present communication reports the presence of authentic Thelypteris repanda (Fée) C.V.Morton for the first time from India. Its distinction from another rare and allied species, Thelypteris birii (R.D.Dixit & Balkr.) Fraser-Jenk. is made clear. T. repanda was recently excluded from India, as all previous reports of it were misidentifications, but it has now been confirmed from two collections from Arunachal Pradesh, one of which had been misreported as a S.E. Asian species, T. megacuspis, in error. Both species are currently known in India from Arunachal Pradesh, with T. birii also occurring just over its border in northern Assam State. Detailed descriptions and photographs of these two species are provided with specimen citations.