304 THE NURSERY LIST. 



Polyanthus. See Primula. 

 Polygala (Milkwort). Polygalace<z>. 



Seeds ; sometimes by division, and by cuttings of young 

 shoots under cover, particularly for tropical species. 



Polygonatum (Solomon's Seal). Liliacecz. 

 Propagated by seeds and by division. 

 Polygonum ( Knot-Grass or Knot-Weed ). Polygonacecz. 



Seeds. The perennials are also easily increased by 

 division of the rootstocks, and by cuttings. See Sac- 

 aline. 



Polypodium (Polypody). Filices. 

 Division usually. See Ferns. 

 Pomegranate (Punica Granatum). Lythracetz. 



Largely by seeds, and all varieties are increased by cut- 

 tings, suckers, layers, and scarce sorts by grafting on a 

 common sort. 



Pomelo, Shaddock (Citrus Decumana). Rutacece. 



Usually grown from seeds, but it may be budded upon 

 pomelo or orange stocks, as in the Orange, which see. 



Pontederia (Pickerel Weed). Pontederiacece. 



Seeds rarely. Mostly by division. See, also, Eich- 

 hornia. 



Poppy. See Papaver. 



Populus (Poplar, Aspen, Cottonwood). Salicacecz. 



Seeds, sown as soon as ripe and raked in, in light soil. 

 Suckers are also used. Most often increased by cuttings 

 of ripe wood, taken in fall and spring. The weeping 

 forms are stock-grafted upon upright sorts, chiefly upon 

 P. grandidentata. 



Portugal Laurel. See Prunus. 



Portulaca (Purslane, Rose Moss). Portulacacete . 



The annuals are raised from seed. Varieties are some- 

 times propagated by cuttings. 



Potato {Solanum tuberosum}. Solanacece. 



Tubers, either whole or variously divided. Also rarely 

 by stem cuttings. See page 60. 



