-INDEX OF GENERA. 639 
Odontia .......cccceeeeeee 489 | Pellia..c..cceccsseceeeoes 353 | Placodium ...........0 367 
Odontoschisma.......... 348 | Peltandra............... 253 | Plagiochila....... we 351 
Cidogonium .......00 397 | Peltigera......... ... 863 | Plagiothecium ......... 343 
CGoothera........s:cccc00 109 | Penicillium...... ... 559 | Plagiotropis ....., wee 445 
Obleria.........,.:0020ee 518 | Peniophora...... +. 493 | Platanus .......... awe 219 
Oidium ....... eee eee ee 658 | Penium ....... « 415 | Platygyrium 344 
Oldenlandia .. - 125 | Pentstemon . ... 184 | Plantago... . 203 
Ombrophila... .. 551 | Penthorum...... ..- LO4 | Pleogpora..... we 523 
Onoclea.........s0eeesee 310 | Pericheena ...... .. 600 | Pleuridium ...... 330 
Onopordon ........s0008 152 | Periconia ....... ... 573 | Pleurocarpus ........... 411 
Onosmodium ........... 178 | Periconia ....... ... 563 | Pleurosigma ...... eee 443 
OOSPOTh.....ceeeceeeeeees 557 | Peridermium ........... 505 | Plewrotenium..... w- 416 
Opegrapha............04. 378 | Periola .......... «. 575 | Plowrightia .......0... 540 
Ophiobolus.............. £25 | Peronospora ............ 584 | Pluchea ......0.:sesceee 141 
Ophioceras.............. 527 | Pertussaria ..... see B70 | Poa... sseivagiveseee 294 
Ophiocytium ........... 613 | Pestalozzia.... 592 | Podophyllum .......... 42 
Ophioglossum ......... 304 | Pestalozziella . 591 | Podosira..... wee 463 
Ophiotheca.. ... 600 | Petunia.. ... 183 | Podosphaca.. see 508 
Opuntia... cesses 111 | Peziza............. ... 544 | Podosporium ........+6 573 
Orchis sisssacszersasciees 233 | Phacidium ... ... 554 | Podostemon ..........0. 212 
Oreoweisia..............5 325 | Phalaris ...... soe 285 | Pogonatum.....csceseeee 317 
Origanum ..........00 198 | Phallus..... wee 498 | Pogonia......cccseccoeeee 233 
Ornithogalum ......... 242 | Phascum ..... ..- 325 | Polanisia....seeseceeee 53 
‘Orobanche ............4. 190 | Phaseolus........ ... 89 | Polemonium....... 175 
Orontium,.........cee 253 | Phegopteris ............ 308 | Polyactis...........c0008 560 
Orthosird ..rccccsscceeee 463 | Philonotia ....... .-. 821 | Polycystis......ssccseee 611 
Orthotrichum .. 331 | Phlebia.. .-. 489 | Polyscytalum.. 
Oryzopsis... .. 286 | Phleum.. ... 288 | Polyedrium . 
Oscillarid. ..ccccseeeeeee 608 | Phlox ......n.sseeeeeee L74 | Polygala .....cccesscecee 
‘Oscillaria ........secce0 609 | Phoma.........0. . 578 | Polygoantum ......... 
Osmorhiza.........cseee 115 | Phoradendron ......... 218 | Polygonum ............ 
Oamunda.....cceee 312 | Phormidium ............ 608 | Polymmnia...........ss000 
OBEY 8! ssvcscevencsvscsese 221 | Phragmidium........... 500 | Polypodium... 
Ox ale vccsocis sess oeeee 73 | Phragmites ..... -. 293 | Polyporus.......eeseseee 
OXYCOCCUB........cc0000s 158 | Phryma ................. 194 | Polysaccum ... 
Phyllachora.... .. 5389 | Polysiphonia ........+0 
Phyllactinia . . 508 | Polythrincium 
P. Phyliitis...... 406 | Polytrichum. 
Phyllophora............ 389 | Pontederia... 
Palavicinia ..........40. 353 | Phyllosticta............. 577 | Populus ...... 
Palmella .......seseeeee 614 | Phymatodocis ......... 414 | Porella .... 
Pandorina............00 410 | Physalis .......cceceeee 181 | Poria.......... 
Panicum .......scsseeeeee 279 | Physalospora .......... 622 | Porothelium ... 
Panmaria ......secsee 364 | Physalospora......... 526 | Porphyra.......... 
PADUA ssvisvesiersasvaones 481 | Physarum.....,.......... 595 | Porphyridium 
Papaver ........scceseeee 44 | Physcia............0004 391 | Portulaca......... 65 
Papulaspora.. . 558 | Physcomitrium ........ 323 | Potamogeton . 257 
Pardanthus .. .. 238 | Physma....... .. 364 | Potentilla.. 96 
Parietaria ............04 218 | Physocarpa.. .- 92 | Poterium 97 
Parmelia ..........cces0s 360 | Physostegia ............ 201 | Pottia.......... 326 
-Parnassia,....sscseceeees 102 | Phytolacca..........ec. 298 | Prenanthes .. 155 
Paspalum ........sseee0 D279. | PAGCOR ccs iussenssccevssoss 301 | Preissia.........ssseceee 354 
Pastinaca ..... seca 118 | Picris..cccccnssesssecenees 153 | Propolis........ceseeces 556 
Patellaria ..........:000 553 | Pilea...... « 218 | Proserpinaca ........... 105 
Pawlonia .ssccccsesecees 184 | Pilidium.... ee 589 | Protococcus........seose 613 
POCIUUB ce cescerecseceese 477 | Pilobolus..... « 593 | Protomyces ........c000 594 
Paxillus .....ccsssecceees 478 | Pimpinella... eee LIB | Prunus .......eeseeeeees 91 
Pediastrum. « 410 | Pinus.......00 «- 800 | Pseudo-ewnotia......000 450 
Pedicularis . .. 189 | Pistillaria. .. .. 496 | Pseudovalsa we. 584 
Pelle aicscciuisevenavesces 3C6 | Pithophora ..... oc 408: | POG OA... icscasisiectesess WA 
