| Oak |
Quercus sp. - a,
e, c, f, n, o |
| Oak Bolete |
Boletus fechtneri - f |
| Oak Fern |
Gymnocarpium dryopteris - e |
| Oakleaf Hydrangea |
Hydrangea quercifolia - e |
| Oak Milkcap |
Lactarius quietus - f, s |
| Oak Mushroom |
Boletus luridus
- a, c, e, f, n |
| Oats |
Avena sativa
- e |
| Obscure Hoya |
Hoya obscura - a |
| Obscure Morning Glory |
Ipomoea obscura - f |
| Ocher Yellow Coelogyne |
Coelogyne ochracea - a, n |
| Ochro |
|
| Ocotillo |
Fouquieria splendens - n |
| Octopus Cactus |
Stenocereus alamosensis - f |
| Octopus Stinkhorn |
Clathrus
columnatus - e, s |
| Oeder's Lousewort |
Pedicularis
oederi - e |
| Oersted's Lockhartia |
Lockhartia oerstedii - f |
| Ogamatoki Tree |
|
| Ohia Lehua |
Metrosideros polymorpha - n, o |
| Okra |
Hibiscus
esculentus - a, f, n, s |
| Old Man of the Woods |
Strobilomyces floccopus - c, e, f, s |
| Old Man Palm |
Coccothrinax crinita - n |
| Oleander |
Nerium indicum
- a, n |
| Oleaster |
Elaeagnus
angustifolia - e |
| |
Elaeagnus
sp. - a |
| Olive-capped Boletus |
Suillus
subolivaccus - f |
| Olive Oysterling |
Panellus stipticus - f, n |
| Oliver's Maple |
Acer oliverianum - a |
| One-flowered Glasswort |
Salicornia pusilla - e |
| Onion |
Allium cepa -
a, c, e, f, n, s |
| Oolong Tea |
n |
| Ombu |
Phytolacca
dioica - s |
| One Colored Vanda |
Vanda concolor - o |
| Onion |
Allium cepa -
a, c, e, f, n, o, s |
| Opium Poppy |
Papaver somniferum
- a, c, e, f, n, s |
| Orange |
Citrus sinensis |
| Orange Birch Bolete |
Leccinium
versipellis - c, e, f, n, o |
| Orange Blossom Orchid |
Sarcochilus falcatus - f, o |
| Orange Bonnet |
Mycena acicula - f, n |
| Orange Caterpillar Fungus |
Cordyceps
militaris - a, c, f |
| Orange Earth Tongue |
Microglossum rufum - a |
| Orange Fan Fungi |
Anthracophyllum archeri - f |
| Orange Jessmine |
Murraya
paniculata - a, o |
| Orange Jewelweed |
Impatiens fulva - f, n |
| Orange Knight |
Tricholoma aurantium - a, f, n, s |
| Orange Latex Milky |
Lactarius
deliciosus - a, c, e, n, o, s f |
| Orange Manjack Tree |
Cordia rickseckeri - n |
| Orange Marmalade Bush |
Streptosolen
jamesonii - o |
| Orange Milkcap |
Lactarius luculentus - f |
| Orange Naval Cap |
Rickenella
fibula - f |
| Orange Peel Fungus |
Aleuria aurantia
- a, c, e, f, n |
| Orange Pore Fungus |
Favolaschia calocera - f |
| Orange Rudolfiella |
Rudolfiella aurantiaca - s |
| Orange Saxifrage |
Saxifraga mutata - e |
| Orange Scaber-stalk Bolete |
Leccinium
versipellis - c, e, f, n |
| Orange Trumpet Vine |
Pyrostegia
venusta - a, e, f, n, s |
| Orange Webcap |
Cortinarius mucosus - c, f, n |
| Orchid Iris |
Iris orchioides - c |
| Orchid Tree |
Bauhinia
monandra - a, n, o |
| |
Bauhinia
variegata - a, f, n,o, s |
| Orchid-Like Blooming Epidendrum |
Epidendrum orchidiflorum - f |
| Oregano |
Origanum vulgare - c, e, f, n |
| Oregon Bitterroot |
Lewisia rediviva
- a, n |
| Oregon Grape |
Mahonia
aquifolium - n |
| Oregon Oxalis |
Oxalis oregana - n |
| Organ Pipe Cactus |
Lemaireocereus
thurberi - a, n |
| |
Stenocereus thurberi - f |
| Oriental Beech |
Fagus orientalis
- a |
| Oriental Chive |
Allium maximowiczii - a |
| Oriental Knight's-spur |
Consolida orientalis - a |
| Oriental Lady’s-thumb |
Persicaria longiseta - a |
| Oriental Paperbush |
Edgeworthia tomentosa - a |
| Oriental Poppy |
Papaver pseudo-orientale - e |
| |
Papaver orientale
-a, e, f, n |
| Ostrich Fern |
Matteuccia
strutiopteris - c, e |
| Outeniqua Yellowwood |
Podocarpus
falcatus - f |
| Outstanding Maxillaria |
Maxillaria
praestans - f, n |
| Oval Coelogyne |
Coelogyne
ovalis - a, f |
| Overlooked Cyrtorchis |
Cyrtorchis praetermissa - f |
| Oxblood Lily |
Rhodophiala
bifida - s |
| Ox-eye daisy |
Leucanthemum
vulgare - a, c, e, f, n, s |
| |
Chrysanthemum
maximum - e, f |
| Oxeye |
Heliopsis
sp. - a, e |
| Oxlip Primrose |
Primula elatior
- c, e, f |
| Oyster Mushroom |
Pleurotus
ostreatus - a, c, e f n,
o |
| Oyster Plant |
Tradescantia
spathacea - a |