G. nigra
G. nigra may refer to:
- Geochelone nigra, the largest living tortoise species, native to seven islands of the Galápagos archipelago
- Gila nigra, the headwater chub, a fish species found in Arizona and New Mexico
Synonyms[edit]
- Gymnadenia nigra, a synonym for Nigritella nigra, an orchid species found in Europe and Israel