INDEX 



485 



Ovule, 109, no, III, 364, 384 

 Oxygen, 3, 13, 15, 20 



Palisade mesophyll 10, 38, 39 

 Pallavicinia, 274 

 Palms, 390 

 Pandanales, 386 

 Pandorina, 168, 169 

 Papaverales, 427 

 Papillae of stigma, 373, 376 

 Papilionaceae, 437 

 Papilionaceous flower, 438 

 Pappus, 468, 472 

 Paraphyses, 198, 230, 244, 289 

 Parasites 59, 204, 224 

 Parenchyma, 11, 73, 76 

 Parmelia, 250 

 Parnassia, 453 

 Pasteur, 154 

 Pea, family, 437 



sweet, 438 

 Peach curl, 219 

 Peat moss, 282 

 Personate flower, 464 

 Pediastrum, 173 

 Penicillium, 205, 216, 220 

 Perennials, 64 

 Perianth, 108, 273, 275, 277, 363, 



367 



Periderm, 247, 248 

 Perigynous, 369, 370 

 Perisperm, 382 

 Perisporiales, 223-225 

 Peristome, 291, 292 

 Perithecia, 216, 221 

 Peronospora, 208, 210 

 Peronosporales, 208 

 Petals, 108, 367, 368 

 Petiole, 7, 8 

 Peziza, 230 

 Pezizales, 230 

 Phaeophyceae, 190 

 Phallales, 249 

 Phallus, 249 

 Phegopteris, 314 

 Philotria, 2 



Phloem, 54, 73, 74, 75, 76 

 Phosphorescence, 241 

 Phlox order, 460 

 Photosynthesis, 1 1 

 Phycomycetes, 206 

 Phyllactinia, 226 

 Phylloglossum, 328 

 Phytophthora, 208, 210 

 Picea, 360 



Pierce, 179 

 Pileus, 242 

 Pinales, 347 



classification of, 360 

 Pine, 348, 350, 351, 353, 354 



wood, 89 

 Pinguicula, 466 

 Pinnularia, 159, 162 

 Pistil, 109, 384 

 Pit, 383 

 Pith, 73 

 Placenta, 373 

 Plankton, 157. 159 

 Planktoniella, 159 

 Plant, nature of, i 



cell, I 

 Plasmodium, 144, 145 

 Plasmopara, 209, 210 

 Plastids, 2, 17 

 Pleurococcus, 171 

 Plowrightia, 227 

 Plumule, 123, 382, 413 

 Pod, 123, 383, 440 

 Poison Ivy, 444, 445 

 Polar nucleus, 112, 113 

 Polemoniales, 460 

 Pollen grains, 109 

 PoUinium, 409, 460 

 Polygonales, 421 

 Polypodium, 314 

 Polyporaceae, 245 

 Polysiphonia, 201, 203 

 Polystichum, 297 

 Polytrichum, 286, 287, 292 

 Pond scum, 175 

 Poplar, leaf arrangement, 26 



order, 414 

 Poppy order, 427 

 Pore, II, 89, 348 

 Porella, 275 

 Potato, 466 



rot, 208 

 Primitive plants, 45 

 Primrose order, 458 

 Primulales, 458 

 Pro-embryo, 344, 356, 381 

 Prosenchyma, 11 

 Protandrous, 366 

 Protection of microspores, 396 

 Proteids, 16 

 Proteid grains, 18, 19 

 Prothallium, 298, 315, 316 

 Protogynous, 367 

 Protonema, 294 

 Protoplasm, function of, 3, 



