442 



INDEX. 



Perigynous, 275 

 Perisperm 234 

 Perithecium, 136-138 

 Peronospora alsinearum (Per-o- 



nos'po-ra al-sin-e-a'rum), 125, 



127, 128 

 Peronospora calotheca, hausto- 



ria of, 324 

 Personatae, 285, 299 

 Petaloideae (Pet-al-oi'de-ae), 251, 



296 

 Phaeophyceae (Phae-o-phy'ce-ae), 



115, 118 



Phloem (Phlo'em), 45, 47, 48 

 Photosyntax, 61 

 Photosynthesis, 61 

 Phycomycetes (Phy-co-my-ce'- 



tes), 128 

 Phyllotaxy, 306 

 Phytophthota infestans (Phy- 



toph'tho-ra in-fes'tans), 126, 



127, 128 

 Picea vulgaris, 212; fertilization 



in, 212 



Pine, new growth, 416 

 Pine, white, 202-213 

 Pines, reforestation by, 378, 379 

 Pinus strobus, 202-220 

 Piper nigrum endosperm and 



perisperm of, 235 

 Plant body, 72, 73; members of, 



73, 74; leaf series, 74; stem 



series, 73; root, 74 

 Plant communities, 410 

 Plasmolysis (Plas-mory-sis), 19 

 Plasmopora viticola (Plas-mop'o- 



ra vi-ti'co-Ja), 125, 126, 128 

 Platycerium alcicorne, 345 

 Pleurococcus (Pleu-ro-coc'cus), 



118, 119 



Plum (family), 276 

 Plumule, 308 

 Podophyllum peltatum, 229-231 ; 



karyokinesis in, 240-243 

 Pollen, of pine, 204 ; of cycas, 



215 ; of trillium, 223 

 Pollenation, 351-367; of pine, 206, 



208 

 Polycarpicae (Pol-y-car'pi-cae) 268, 



297 

 Polygonacese (Po-lyg-o-na'ce-ee), 



267, 297 



Polygoniflorae, 267, 297 

 Polygonum sagittatum, 267 



Polymorphic, 135 

 Polypetalous, 278 

 Polypodium vulgare, 170, 239 

 Polyporus (Pol-yp'o-rus), 338 

 Pomaceae, 276, 295, 298 

 Pontederia, 406 

 Poppy (family), 271 

 Porella, 155 

 Portulacaceae, 268, 297 

 Potential energy, 67 

 Powdery mildews, 136 

 Primrose, 355, 356 

 Primula, 284; pollenation of, 356 

 Primulaceae, 284, 299 

 Primulinas, 284, 299 

 Procambium strands, 47 

 Progeotropism (Pro-ge-ot ro- 



pism), 82, 83 

 Promycelium (Pro-my-ce li-um), 



134-136 



Proterandrous, 360 

 Proterandry, 362 

 Proterogynous, 360 

 Prothallium, of ferns, 176-182; 



of pine, 209, 210; of cycas, 214, 



215; of angiosperms, 228-233 

 Protococcoideae (Pro-to-coc-coi'- 



de-ae), 118, 119 

 Protococcus (Pro-to-coc'cus), 118, 



119 

 Protonema (Pro-to-ne'ma), 163, 



178, 180 

 Protoplasm, 1-12; movement of, 



7-1 1 



Prunus virginiana, 277 

 Pteridophyta (Pter-i-doph'y-ta), 



200, 201 



Pteris aquilina, 178 

 Pteris cretica, 245 

 Pteris serrulata, spores of, 177 ; 



embryo of, 183, 186 

 Puccinia graminis, 129-136 

 Pumpkin, roots of, 77, 78 

 Pumpkin seed, germination of, 



309-311 

 Purslane, 268 

 Pyrenoid, 2 

 Pyrolaceae, 283, 299 

 Pyrola elliptica, 283 



Quercus rubra, 263 

 Quillworts, 196-198 



Ranunculaceae, 268, 294, 297 



