31 



274 Ostrya Micheli. 



1 virginica W. Iron Wood. Hop Horn Beam. 



275 Oxalis L. 



1 acetosella L. Wood Sorrel. Conway. 



2 stricta Jacq. Yellow Woodsorrel. 



3 violacea L. Amherst. 



276 Oxycoccus Pers. 



1 macrocarpus Ph. 



2 vulgaris Pers. 



3 hispidulus Pers. Gaullheria hispidula Muhl. 



P. 



277 Panax L. 



1 quinquefolium L. Ginseng. Conway. 



2 trifolium L. Dwarf Ground Nut. 



278 Panicum L. 



1 acuminatum Muhl. 



2 agrostoides Muhl. 



3 capillare L. 



4 clandestinum L. 



5 crus-galli L. Barn Grass. 



6 dichotomum L. 



7 depauperatum Muhl. 



8 geniculatum Muhl. 



9 involutum Torrey. 



10 latifolium L. 



11 macrocarpon Torrey. 



12 nervosum Muhl ? 



13 nitidum Lmk. 



14 virgatum L. 



279 Parietaria L. 



1 pennsylvanica L. Pellitory. Sugar Loaf. 



280 Parnassia L. 



1 caroliniana Mx. Parnassus Grass. 



281 Paspalum L. 



1 setaceum Mx. Paspalon Grass. 



282 Pastinaca L. 



§ 1 sativaL. Parsnip. 



