Nitella opaca is a species of algae in the family Characeae.

Nitella opaca is a dioecious species very similar to Nitella flexilis and difficult to distinguish from it.

[1] Nitella opaca has been observed in fresh waters, mostly lakes.

[2] From the Latin adjective opaca, meaning "opaque", "not shining".

This green algae-related article is a stub.