New Record of Equisetum ramosissimum subsp. debile from Lower Gangetic Plain, West Bengal, India and Conservation Approach

A recent survey for pteridophytic flora in the lower Gangetic plain of West Bengal, India reports the natural occurrence of Equisetumramosissimum Desf. subsp. debile (Roxb. Ex Vauch.) Hauke (Equisetaceae) from alluvial Gangetic zone of North 24 Parganas district (22°55′39.00″N and 88°26′14.94″E) which adds new record to the existing database of pteridophytic flora in the region. Regular observations show that the population of E. ramosissimum is sustained completely by vegetative means due to non-formation of reproductive organ i.e. strobilus in an individual plant in any season. The community analyses through standard ecological methods reveal heterogeneous phyto-assemblages in both winter and rainy seasons, however, seasonal variations are observed in species diversity and frequency. Simpson’s Index of Diversity in both plant communities suggests diverse species richness and evenness in the area. Importance Value Index depicts ecological dominance of E. ramosissimum in both seasons. The plant has significant positive correlation with angiospermic taxa, Mikaniamicrantha and Typhaangustifolia in winter and rainy seasons, respectively but is negatively correlated with Xanthium indicum and Desmostachyabipinnata, correspondingly. These observations may be taken into consideration for in situ conservation of the species. Systematic conservation plan is suggested to protect this newly revealed taxon, E.ramosissimum subsp. debile which demands regular awareness program among local people for continued future sustainability as the area is regularly invaded by human footsteps. Finally, the present investigation may motivate the young workers for field study to explore the nature in better way. © 2016, The National Academy of Sciences, India.