Below I have selected a few plant genera beginning with the letters N and O that I think could have potential use as a name choice.
Plant names:
A I B to C I D to F I G to J I K to M I N to O I P I R to S I T to V I W to Z
Nandina - A hardy shrub, commonly known as sacred bamboo (although it isn't a bamboo at all). It's name comes from the Japanese name nandin. In China and Japan the plant was long used to ward off bad luck.
Neillia - Named after Scottish botanist Dr Patrick Neill (1776-1851).
Nemophila - Commonly known as "baby blue eyes" plants. Derived from the Greek νέμος (nemos) 'grove' and φίλος (philos) 'loving'. It could be considered a translation for the English surname Lovegrove.
Neolitsea - "New Litsea". Part of the laurel family, native to Asia and Australia. Cassia is a species name.
Nerium - From the Ancient Greek name for Oleander. Oleander is now the species name, which derived from olea, the Greek name for the olive due to the similarity in looks, and makes an interesting alternative to Oliver and Alexander.
Nicandra - Part Nicole, part Alexandra. These night-shade family plants are named after Nicander (Nikandros) of Calophon (c.100 BC), ancient writer on plants and antidotes. The Greek name Nikandros means "man's victory", from νικη (nike) 'victory' and ανδρος (andros) 'a man'.
Niphaea - Derives from the Greek νιφος (niphos) 'snow', in reference to the plants' white flowers.
Nitella - Aquatic plants derived from the Latin nitere 'shining, glittering'.
Nolana - "Little bell", a diminutive of the Latin nola 'small bell'.
Nolina - Named after P.C. Nolin (c.1755) a French writer on agriculture.
Olax - Derived from the Greek αὖλαξ (aulax) 'furrow' via the Doric olax, believed to be so named because of the two-ranked leaves. Olaf with the fashionable 'x'.
Olea - The Latin name for olive, ultimately from the Greek ἐλαία (elaia).
Oleandra - "Oleander-like," due to its similarity to oleander leaves.
Olearia - Commonly known as daisy bush. Some derive its etymology from olea, due to similarity of the leaves. Others believe it to be named after German scholar Adam Olearius (Adam Oehlschlaeger).
Olyra - A genus of grass from the Greek ολυρα (olyra), a type of grain. She's somewhere between Olivia and Lyra.
Orixa - Believed to be derived from the Japanese vernacular name for orixa japonica.
Orthilia - The etymology is uncertain, but it possibly derives from the Greek ορθρος (orthos) 'straight, upright'.
Ottelia - Similar to fashionable Ottilie, the name is the Latinised form of Ottel-ambel, the ancient Malabar vernacular name for the plant.
Ourisia - Named after Governor Ouris (d. 1773) of the Falkland Islands, where the genus was first found.
Genus names that were already in use as first names include Narcissus, Nerine, Nymphe, Nyssa and Ophelia.
