Brassica nigra, the black mustard, an annual weedy plant cultivated for its seeds, which are commonly used as a spice
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Betula nigra, a species of birch native to the eastern United States from New Hampshire west to southern Minnesota, and south to northern Florida and east Texas
Sambucus nigra | Centaurea nigra | Pinus nigra | Juglans nigra | Fraxinus nigra | Carex nigra | Brassica nigra | Populus nigra | Tinea nigra | Prosopis nigra | Porta Nigra | ''Populus nigra'', originating in the United States from plantings by André Michaux | M. nigra | Mined leaf of ''Centaurea nigra | Leaf of ''Ballota nigra | Hoplocorypha nigra | Gila nigra | Betula nigra | A shoot of ''Centaurea nigra |
Gila nigra, the headwater chub, a fish species found in Arizona and New Mexico
Hoplocorypha nigra, a praying mantis species found in the region of the Congo River
The SRV serotype-2 was found in endemic infections of pig-tailed monkey (M. nemestrina), cynomolgus macaques, Japanese macaque (M. fuscata), at Washington NPRC, and in rhesus and Celebes black macaques (M. nigra) at Oregon NPRC.
Ballota species are used as food plants by the larvae of some Lepidoptera including Coleophora case-bearers: C. ballotella, C. lineolea (which has been recorded on B. nigra) and C. ochripennella.