There's a great article here that could answer it better than I ever could. Although it's more than just Japanese mythology:
http://ladymaggic.podomatic.com/entry/2008-05-25T03_23_02-07_00
~origamifolder.com
water lily
The Japanese word for flower is "Hana"
Monet painted the Japanese bridge over his water lily pond a number of times between 1889-1890.
.water chestnuts .seaweed .algae .bamboo .lily pads .lotus .japanese iris .dwarf cattail
黒百合 /ku ro yu ri/ means black lily in Japanese.
'Dancing lily' translates to踊ã£ã¦ã‚‹ãƒ¦ãƒª (odotteru yuri) in Japanese.
The words night lily are said in Japanese as yoru yuri. These words are said in Italian as notte giglio.
The water lily leaf does not have a special name. It can be referred to as a "water lily leaf' or as the leaf of a certain water lily species.
Small Lily
flower/water= water lily
flower/water= water lily
lillies are a ground plant and lily pads are a water plant