1. Tropical American terrestrial fern with leathery lanceolate fronds; sometimes placed in genus Polybotrya
   - hart's-tongue, hart's-tongue fern, Olfersia cervina, Polybotrya cervina

Type of: fern

• genus Nerium
• genus Nerodia
• genus Nesokia
• genus Nestor
• genus Neurospora
• genus Neurotrichus
• genus Nicandra
• genus Nicotiana
• genus Nidularia
• genus Nierembergia
• genus Nigella
• genus Nigroporus
• genus Nimravus
• genus Nipa
• genus Nitella
• genus Nitrobacter
• genus Nitrosomonas
• genus Noctiluca
• genus Noctua
• genus Nolina
• genus Nomia
• genus Nopalea
• genus Nostoc
• genus Notechis
• genus Notemigonus