673 



Potentilla, 348 

 Poulard wheat, iii, 112 

 Prickly ash, 475 



cucumber, 617 

 Privet, SSI 

 Profichi, 272 

 Prophyllum, 80 

 Prop roots, 16, 159 

 Proso, 213 



millet, 210 

 Protandry, 170 

 Protease, 142 

 Proteose, 105 

 Protogyny, 170 

 Protoplasm, 9 

 Protoplasmic membrane, 6 

 Protoplast, 6 

 Prunes, 398 

 Prunus, 394 



americana, 400 



amygdalus, 410 



angustifolia, 401 



armeniaca, 405 



avium, 402 



besseyi, 404 



cerasifera, 400 



cerasus, 402, 403 



cuneata, 404 



dasycarpa, 407 



domestica, 398 



emarginata, 404 



hortulana, 400 



insititia, 399 



key to main groups of, 394 



mahaleb, 404 



mume, 407 



munsoniana, 401 



nigra, 401 



pennsylvanica, 404 



persica, 407 



pumila, 404 



sibirica, 407 



triflora, 400 

 43 



Psedera tricuspidata, 33 

 Pseudomonas radicicola, 413 

 Psilotales, 64 

 Ptelea, 475 

 Pteridophytes, 62 

 Pumpkin, 613 



field, 613 



mammoth, 613 



Valparaiso, 613 ' 

 Purple apricot, 407 



cane raspberry, 337 



clover, 436 



vetch, 428 

 Pyrus, 384 



communis, 384, 385 



serotina culta, 384, 385 



Quackgrass, 21, 70 

 Quamoclit quamoclit, 554 

 Quince, 388 



Rabbit-brush, 625 

 Raceme, 56, 78 

 Rachilla, 79 

 Rachis, 79, 92 

 Radicula, 344 



armoracia, 345 



nasturtium-aquaticum, 345 

 Radicle, 57 

 Radish, 341 



garden, 341 



rat-tailed, 343 



wild, 342 

 Ragi millet, 210 

 Raisin grape, 499, 500 

 Raisins, 501 

 Raphanus, 341 



caudatus, 343 



raphanistrum, 342 



sativus, 341 

 Raspberry, 357 



American red, 357 



black cap, 357 



