Aquatic plant which gives its name to an asana in yoga (5)
I believe the answer is:
lotus
(Other definitions for lotus that I've seen before include "Plant that mythically induces languor" , "Cross-legged position adopted in yoga" , "Large water lily" , "Fruit of forgetfulness - water lily - car marque" , "Mythical fruit inducing state of luxurious dreaminess" .)