416 



Populus grandidenta, Mx. Tree poplar. 



tremuloides, Mx. White poplar. American aspen. 

 Porcelia triloba, Persoon. Pawpaw. Custard apple. 

 Portulacca oleracea, Linn. Purslane. 

 Potamogeton heterophyllum, Schreber. 



natans, Linn. Pond-weed. 



lucens, Linn. 



pectinatum, Linn. 



perfoliatura, Linn. 



zosterifolium, Trinius. 

 Potentilla anserina, Linn. Tansey cinquefoil. Silver leaf, 



arguta, Pursh. 



canadensis, Linn. Five-finger. 



comarum, D. C. Marsh five-finger. 



fruticosa, Linn. Shrubby cinquefoil. 



norvegica, Linn. Cinquefoil. 

 Prenanthes lacemosa, Mx. 



serpentaria, Pursh. 

 Prinos verticillatus, Linn. Winterberry. False alder. 

 Prunella vulgaris, Linn. Heal all. Self heal. 

 Prunus Americana, Marshall. Meadow plum. 



depressa, Pursh. Sand cherry. 



obovata. Beck. 



pennsylvanica, Alton. 

 Ptelea trifoliata, Linn. 

 Pteris aquilina, Linn. Common brake. 

 Pycnanthemum virginicnm, Persoon. Virginian thyme. 

 Pyrola elliptica, ISTutt. White wintergreen. 



rotundifolia, Linn. Shin-leaf. 



secunda, Linn. One-sided shin-leaf. 



umbellata, Linn. Prince'.s pine. 

 Pyrus coronaria, Linn. Crab apple. 



melanocarpa, Ww. 



Q. 



; 



Quercus alba, Linn. White oak. 



bicolor, Ww. Swamp white oak. 



