AaronT

hippuris probably means something in latin that would cause the two to have similar names. For instance Hemianthus callitrichoides. The "oides" part means looks like. So it looks like callitriche.

jaidexl

Great info

ed seeley

This plant seems to have been named due to it's similarity to the Mare's tails and was given a specific name to allude to that similarity. There are many, many of examples of this in latin names. As Aaron said, they are often done with suffixes like -oides, but not always.

Hippurus means horse, hence the Mare's tail was said to resemble a horse's tail (though I don't really see it myself!)
Strangely (to my mind) the Horsetails are in the genus Equisetum and this is derived from Equus which is that latin name for horse.
Obviously the people who named these two groups of plants had a thing about horses...

jazzlvr123

looks similar to some rotala pusilla I got

AaronT

A little bit. Pusilla has thicker leaves if you can believe it. This is the finest leaved Rotala I've ever seen or kept. I still have a couple stems going.

Wö£fëñxXx

Agreed, it is a very petite plant, it will grow to the
surface in no time but for stem and needle structure it
is very tiny/petite.
Very cool plant, but what plant isn't.