Common Name

Scientific Name

Common Name

Scientific Name

Oak

Quercus spp.

Old man's beard lichen

Usnea alpina

Oak, black

Quercus velutina

Oleander

Nerium oleander

Oak, blackjack

Quercus marilandica

Olive

Olea europea

Oak, bur

Quercus marcocarpa

Olive, Russian

Elaeagnus angustifolia

Oak, chinkapin

Quercus muehlenbergii

One seed juniper

Juniperus monosperma

Oak, live

Quercus virginiana

Onion

Allium сера

Oak, pin

Quercus palustris

Opium poppy

Papaver somniferum

Oak, post

Quercus stellata

Orange, mock

Philadelphus coronarius

Oak, red

Quercus rubra

Orange, navel

Citrus sinensis

Oak, scarlet

Quercus coccinea

Orange, osage

Madura pomifera

Oak, shingle

Quercus imbricaria

Orange, sweet

Citrus sinensis

Oak, shumard

Quercus shumardii

Orchard grass

Dactylis glomerata

Oak, white

Quercus alba

Orchid

Cattleya spp.

Oat

Avena sativa

Orchid

Cymbidium spp.

Obedience plant

Physostegia virginiana

Orchid

Dendrobium spp.

Ocotillo

Fouquieria splendens

Orchid, vanilla

Vanilla planifolia

Oedogonium

Oedogonium spp.

Oregon grape

Mahonia aquifolium

Ohio buckeye

Aesculus glabra

Oriental sycamore

Platanus orientalis

Oil palm

Elaeis guineensis

Osage orange

Madura pomifera

Okra

Hibiscus esculentus

Ostrich fern

Matteuccia struthiopteris

Oyster mushroom

Pleurotus ostreatus