Post Oak      

Potato Dwarfdandelion          

Poverty Brome          

Poverty Dropseed          

Poverty Oatgrass          

Poverty Rush      

Prairie Buttercup          

Prairie Clover          

Prairie Coneflower          

Prairie Cordgrass      

Prairie Dropseed      

Prairie Fleabane      

Prairie Goldenrod          

Prairie Groundsel          

Prairie Rosinweed          

Prairie Sunflower          

Prairie Tea          

Prairie Threeawn          

Prairie Wedgescale      

Prairie Willow      

Pretty Sedge          

Prickly Bog Sedge      

Prickly Fanpetals          

Prickly Hornwort          

Prickly Lettuce          

Prickly Russian Thistle          

Pricklyash          

Pricklypear          

Pricklypoppy          

Pride Of Ohio      

Pride-of-rochester          

Primrose Peerless          

Primrose-willow          

Princesstree      

Privet          

Procession Flower          

Proso Millet      

Prostrate Blue Violet          

Prostrate Knotweed          

Prostrate Pigweed          

Prostrate Sandmat          

Prostrate Ticktrefoil          

Prune-fruit Sedge          

Pteroglossaspis