C. nigra
# C. nigra

C. nigra may refer to:

## Animals

* Cardiocondyla nigra, an ant species in the genus Cardiocondyla
* Ciconia nigra, a large wading bird species
* Coracopsis nigra, a black coloured parrot species native to Comoros, Madagascar, Mayotte and Seychelles
* Chelonoidis niger, the largest living species of tortoise, often historically misspelled as "nigra"

## Plants

* Carex nigra, a perennial plant species native to wetlands of Europe and Siberia
* Crataegus nigra, a hawthorn species
* Centaurea nigra, a flowering plant species
