1. Eleocharis?The second one here is kind of thorny but not hard thorns
Najas marina....man you nailed I looked for images on the web and is the same thanks. I don't see a lot of people using it1st 3:
-Hydrocotyle? Could be Centella but hard to say from photo
-Does it smell like burned rubber bands?
-Eleocharis - can't say species though