P. nigra

P. nigra may refer to:

Animals

 * Penelopina nigra, the Highland guan, a bird species
 * Petrotilapia nigra, a fish 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
 * Pomarea nigra, the Tahiti monarch, a bird species
 * Porzana nigra, an extinct bird species

Plants

 * 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