Pteridophytes of Namdapha National Park, Arunachal Pradesh, N.E. India

Namdapha National Park in eastern Arunachal Pradesh near the Myanmar border is perhaps the most bio-diverse park in India, being situated at the edge of the region of the centre of diversity of Sino-Himalayan species and also being connected to the S.E. Asian (Malesian) flora through the adjacent mountain ranges of Myanmar. The area has very high rainfall and a great range of altitude (from c. 300 m to 4500 m). Despite increasing human pressure, the Park still contains large areas of species-rich, pristine tropical-type rain-forest and temperate forest, along with secondary forest. It is thus a notable haven for a very great diversity of pteridophytes (ferns and allies, including lycophytes), which form an obvious and often dominant part of the ground vegetation, with tree-ferns (Cyathea) above. However only the lower regions have been explored scientifically, up to c. 500 m altitude. A remarkable nine tenths of the altitude-range of the park remains entirely unexplored and its high-altitude Sino-Himalayan flora, still quite unknown, must be immensely rich, including the pteridophytes. A checklist of pteridophytes of the park is given here as known so far from all relevant herbarium-collections and from the authors’ own collections, altogether 184 taxa, though well over twice that number should be expected if a far-reaching scientific expedition could take place, which has not so far occurred.