cclvi PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



Plum saw-fly, 39 



silver-leaf, 385 

 tortrix, 29, 30, 39 

 weevil, 29, 31 

 Plumbago Larpentae, 419 

 Plums, origin of American, 526 



time of flowering, 371 

 " Pocket Synopsis of the Families 

 of British Flowering Plants," by 

 W. B. Grove, reviewed, 130 

 Podocarpus andina, 8 

 Podophyllum Emodi fruit, cix 

 Podosphaera leucotricha, 369 

 Poisonous effect of one crop on another, 

 374 



Pollination in orchards, 382 



bees, 151 

 Polyanthus fasciated, cv, cvi 

 Polygonum aviculare self -fertile, 523 



bistortoides, 25 



lichiangense, 206 



sp. for rock garden, 384 



vacciniifolium, 418 

 Polypodium Dryopteris plumosum, 



A.M., ccviii 

 Polyporus lacteus on yew, cxcviii 



Schweinitzii, 379 

 Polystachya paniculata, 526 

 Polystichum angulare Clarkii, cxxvii 

 Poplar crown gall, 161 



food for pests, 36, 39 



gall, cvii 



" Popular Hardy Perennials," by T. W. 



Sanders, reviewed, 487 

 Populus x canadensis, 15 



deltoides, 15, 153 



italica, 15, 19, cvii 



lasiocarpa, 526 



mycorrhizas, 159 



nigra, 15, cvii 



var. viridis, 15 

 x serotina, 15 



trichocarpa, 21 

 Potash salts, 162, 373 

 Potassium cyanide, 156 



manuring with its salts, 165 

 Potato ' Arran Chief,' A.M., cxvi 



bacterial attack on, 523 



black canker, 382 



black-leg, 161, 383 



black-speck scab, 162 



blight, 382, 526 



in India, 162 



curly dwarf, 383 



degeneration, 465 



diseases, 382, 526 



' Dobbie's Provost,' 125 



'Duke of York,' A.M., 162, 

 cxiv 



' Epicure,' 162 



' General Joffre,' cxvi 



' Iron Duke,' 162 



' King Edward VII.,' 162 



leaf roll diseases, 383 



'Midlothian Early,' A.M., cxiv 



'Old Yellow Ashleaf,' A.M., 

 cxvi 



pink rot, 382 



' President,' 162 



Potato scab, 162, 526, 527 



sclerotium disease, 382, 526 

 spindling-sprout disease, 383 

 spraying, 383 



' Stirling Castle,' A.M., cxvi 

 ' Stretton No. 20,' A.M., cxvi 

 tubers inside old tuber, cvii 

 ' Up to-date,' 162 

 varietal immunity, 526 

 wart disease, 162, 525 



on foliage, cxcvii 



wilt, 526 



'Wolfe's Secundus,' A.M., cxvi 

 Potatos, blindness in, cxciv 



early and mid-season tried at 



Wisley, 1915, 290 

 effect of exploding soil in bed, 

 124 



formalin treatment of seed- 

 tubers, 375, 526 

 manures for, 162 

 storing of, 527 

 tried at Wisley, 290, cxiii 

 Potentilla, 425 



flabellifolia, 25 

 sp. in Yunnan, 201 

 Poterium obtusum, A.M., cxxxi 

 Poultry manure, xliv 

 " Practical Book of Garden Archi- 

 tecture," by P. W. Humphreys, 

 reviewed, 132 

 " Practical Book of Outdoor Rose- 

 growing," by G. C. Thomas, re- 

 viewed, 134 

 Praepodius amabilis, 533 

 Prairie, replacement of vegetation on, 

 527 



Preliminary Recognition Certificates, 

 470 



Prickly pear, see Opuntia 

 Primula acaulis, heterostylism in, 527 

 x ' Adonis,' A.M., lxv 



aemula, 528 



alsophila, 528 



alta, 528 



amethystina, 203 

 annulata, 528 

 bathangensis, 528 

 Beesiana, 205, 206 

 bella, 203 

 blattariformis, 205 



var. Duclouxii, 528 

 brevifolia, 163, 203, 207 

 bullata, 205 



Bulleyana, 206, 425, cxxiii 



magnifica, cxix 

 caerulea, 203 

 Calderiana, 528 

 calliantha, 207 

 capitata, 528 

 carniolica, lxv 

 celsiaeformis, 528 

 cephalantha, 528 

 chionantha, 528 

 cinerascens, 201 

 citrina, 528 

 compsantha, 528 

 conspersa, 528 

 coryphaea, 52 



