Psilophyton princeps—Pulsatilla nigricans 
Psilophyton princeps Richt.* 588, 596 
— robustius 574 
Psilotaceae 18 
Psilotinae 14 
Psittacanthus 433, 434 
— Kerberi 432 
Psoralea 419 
— tlaccida 410 
Psorospermum 395 
Psychine 348 | 
Psychotria 505, 506, 507 
— florestana 504 
— Hoehnei 504 
— Pervitlei 504 
— refractistipula 508 
Ptelea 510 
— trifohata 56 
Pteleopsis myrtifolia 304 
Pterideae 18 
Pteridium aquilinum 22 
Pteridophyta 19 
Pteridospermeae 123 
Pteris N. A. 33 
— aquilina II, 149 
— — /.crispa II, 200 
— eretica Childsii 29, 30 | 
= Zzmultıhdar 1 93 
— longifolia 631 
— pacajensis 566 
— pumila 30 
— tremula 30 
Pterisanthes coriacea 561 
Pterobalanus toscanus 566 
Pterocarpus 416 
—- ormosioides 410 
— Soyauxli 410 
Pterocarya 398 
— rhoifolia 398 
— stenoptera 398 
Pterocephalus 359 
— melanobasis 308 
— Nestorianus 358 
Pterochiton 108 
Pteroeymbium 537 
Pteronia 97 
Pterophyllum Andraeanum 582 
— Kudernatschi 586 
— rotundatum 586 
Pterospermum celebicum 537 
Pterostemma 222 
sol 
Pterostemon . 523 
Pterostemonaceae 523 
Pterostylis 219 
—- coneinna 229 
ı — decurva 216 
| —- praecox 229 
ı — Torreyana 229 
ı Pterostyrax 539 
Pterotaberna 251 
Pterygiella 109 
ı Pterygophyllum lucens II, 127 
Pterygopteris Johansson N. G. 582 
— Angelini (Nath.) Joh.* 582 
Pterygota 537, 538, 676 
ı Ptiloria 312 
Ptychocarpus 584 
Ptychococeus 232 
Ptychosperma 235 
Ptychotis ajowan 399 
— heterophylla II, 188 
Ptyssiglottis 242 
Puceinellia 50, 188. — II, 32 
— manmalamg, IUL, 8% 
— retroflexa II, 32 
Puceinia graminis tritici 626, 701 
— mirabilissima II, 157 
Pucciniastrum americanum 702 
Pugionium 350 | 
Pulicaria 97 
Bulmonanlan 73 SS T16 
— angustifolia 264 
— — azurea 264 
— jurana II, 76 
| — monana 10, 76, OU 
— obscura II, 42 
— Mund 2 — 
— — var. obscura x vulgaris II, 69 
| — stirlaca II, 89 
— vulgaris II, 76 
 Pulsatilla 99, 127. — II, 100, 191 
| — ajanensis 99 
ı — alpina 99. — II, 100 
| — — Mr, bonmanae, Jens U, 108 
— grandis II, 100 
— grandis X nigricans II, 100 
— Halleri 103 
—  montana 486. — II, 100 
— nigricans II, 100 
— — var.coerulea J. Wagner* II, 115 
— nigricans X patens II, 100 
