P. nigra

P. nigra may refer to:

Animals

Penelopina nigra, the Highland guan, a bird species
Petrotilapia nigra, a fish species
Porzana nigra, an extinct bird species
Phelsuma v-nigra v-nigra, a small diurnal subspecies of geckos
Phylidonyris nigra, a bird species that inhabits the east coast and the south-west corner of Australia

Phyllostachys nigra, a bamboo species
Pinus nigra, a variable species of pine, occurring across southern Europe from Spain to the Crimea, and also in Asia Minor, Cyprus and locally in the Atlas Mountains of northwest Africa
Populus nigra, the black poplar, a tree species
Prosopis nigra, a South American leguminous tree species that inhabits the Gran Chaco ecoregion in Argentina and Paraguay
Prunus nigra, a tree species native to eastern North America from New Brunswick west to southeastern Manitoba and south to Connecticut across to Iowa