FLOWERING PLANTS. 19 



POA, L. meadow grass. 



compressa, L. blue grass. 



trivialis, L. rough meadow grass. 

 PODOPHYLLUM, L. may-apple. 



peltatum, L. 

 POGONIA, Juss._ (triphora, If.) 



pendula, Lind. three-bird orchis. 

 POLANISIA, Raf. false mustard. 



graveolens, Raf. 

 PLATANUS, L. sycamore-tree. 



occidentalis, L. 



POLEMONIUM, Tourn. Greekvalerian. 

 reptans, L. 



POLYGALA, Tourn. milkwort. 



senega, L. seneka snakeroot. 

 POLYONATUM, Tourn. Solomon's seal. 



canaliculatum, Pursh. great Solomon's seal. 

 POLYGONUM, L. knotweed; persicaria. 



virginianum, L. wand-spiked persicaria. 



pennsylvanicum, L. hairy-stalked persicaria. 



arifolium, L. halbert-leaved persicaria. 



convolvolus, L. bindweed. 



sagittatum, L. arrow-leaved tear-thumb. 



hydropiper, L. waterpepper ; smartweed. 



persicaria, L. spotted persicaria. 



aviculare, L. knot grass; goose grass. 



POLYMNIA, leaf-cup. 



canadensis, L. white leaf-cup. 



uvedalia, L. large yellow leaf-cup. 

 POLYPODIUM, L. polypody. 



hexagonopterum, Michx. 

 POPULUS, Tourn. poplar; aspen. 



grandidentata, Michx. large-toothed aspen. 



angulata, Ait. angled Cottonwood. 

 POTAMOGETON, Tourn. pondweed. 



natans, L. broad-leaved pondweed. 



pectinatus, L. fennel-leaved pondweed. 



compressus, L. (zosterifolium, Schum.) 

 PORTULACCA, Tourn. purslane. 



oleracea, L. 

 POTENTILLA, L. cinquefoil; five-finger. 



canadensis, L. common cinquefoil. 



norwegica, L. 

 PRUNELLA, L. self-heal. 



vulgaris, L. common self-heal or all-heal. 



