Phyto-sociological studies on pistia stratiotes l. var. cuneata engl. (araceae) in purba Medinipur district, West Bengal, India

Pistia stratiotes L. var. cuneata Engl. is an aquatic, floating, stemless, stoloniferous and huge herb found growing in different parts of the tropical as well as subtropical regions of India. It has immense diverse economic potentialities. Phyto-sociologically it is very much related with six constant associates like Ipomoea aquatica, Eichhornia crassipes, Lemna perpusilla, Enhydra fluctuans, Typha elephantina, Marsilea quadrifolia and 31 other plants like Alternanthera sessilis, Cyperus rotandus, Monochoria hastata, etc. which are known as flexible associates. Maximum association was noted with Lemna and Eichhornia and minimum with Alisma and Nymphaea during our present studies. Relative Density (RD), Relative Frequency (RF) as well as Importance Value Index (IVI) of the said species are also discussed in this paper.