What does "frogbit" mean?

Hydrocharis morsus-ranae, with roundish leaves and small white flowers. It is free-floating.

Frogbit

Common synonyms include: hydrocharis morsus-ranae, amazon frogbit, frog's-bit, limnobium, limnobium spongia.

noun

noun ·Rare ·Advanced level

Noun

1
Hydrocharis morsus-ranae, with roundish leaves and small white flowers. It is free-floating. countable, uncountable
2
European floating plant with roundish heart-shaped leaves and white flowers wordnet
3
An American plant, Limnobium spongia, with is also free-floating. countable, uncountable
4
A South American plant, Limnobium laevigatum. countable, uncountable

From frog + bit, perhaps to explain the notched petal tips.