As i can examine its looks like a creeping, rhizome plant. Seller doesnt know the name but he said it likes watery humid enviroment. I will try it in my nano paludarium tank. A member of fern species maybe? Anybody can identify please? Thanks in advance.
Looks to me like it could be Leptinella squalida (possibly the cultivar 'Platt's Black'), a member of the Asteraceae (daisy) family. It makes a useful ground cover plant in the shade.
Missouri Botanical Garden's page at Leptinella squalida 'Platt's Black' - Plant Finder says for Leptinella squalida "Synonymous with and formerly known as Cotula squalida."
Plant it outside in the sun and you'll find it forms a very dense mat with a more even foliage colour, like this http://www.cfgphoto.com/photo-72582.htm . It can even be mown as a lawn substitute and has been used as a surface for lawn bowls.
