INDEX OF THE GENERA, 



39"< 



Ophioglossum 386 



Orchis 316 



Origanum » . 236 



Ornithogalum 151 



Ornus 17 



Orobanche 244 



Orontium 155 



' Oryzopsis . . . > 46 



Osmunda 385 



Ostrya 355 



Oxalis 194 



Oxycoccus 168 



Panax 129 



Panicum 66 



Parietaria 352 



Parnassia 141 



Paspalum 47 



Passiflora 253 



Pastinaca 137 



Pcdieularis 242 



Pcnthorum 1 95 



Pentstemon 243 



Peplis i. 



Pcriploca 124 



Phacclia 106 



Phalangium 151 



Phalaris 54 



Phaseolus. 270 



Phleum 54 



I'hlox ... 108 



Phryma 238 



Phyllanthus 361 



Phragmitcs 55 



Physalis 110 



Phytolacca 196 



Pinus 359 



Piptatherum 48 



Pisum 263 



Plantago 84 



Platanua 355 



Poa 56 



Podophyllum 217 



Podostcmum 



Pogonia 390 







Polemoniutn 109 



Polygala 



gooum 171 



Polymnia >l I 



folypodium 



I'olypogon 



Pontcdcria 150 



Populus 375 



Portulacca 216 



Poiamogeton 88 



Potentilla 209 



Prenanthes 277 



Primula 103 



Pnnos 148 



Proserpinaca 74 



Prunella 236 



Prunus 198 



Psamma 53 



Pit-lea 86 



Pteris 384 



Pterospora 185 



Pulmonaria 100 



Pycnanthemum 235 



Pyrula 185 



Pyrus 203 



Quercus 357 



Ranunculus 225 



Rap jatius 252 



Rhamnus 120 



Rhexia 165 



Rhododendron 183 



Rhodora 184 



Rhus 140 



Rhynchospora 41 



Riocfl 121 



Rivina 86 



Robinia 271 



llochelia 102 



Rosa 205 



liubus 206 



Ruellia 240 



Rudbeckia 310 



Rumex 162 



Ruppia 89 



Sahhatia 105 



Sagina 87 



Sagittaria 355 



Saiicornia 13 



Salix 365 



Salsola 131 



Balrk 23 



SnU iriiu. 390 



S.umImu'ii* 139 



Sniuolus 104 



Sanguinaria 



Banguborba 82 



Baotcala 1S9 



I. I ' 



