POTENTILLA PRUNUS. 305 



Potentilla, including Horkelia (Cinquefoil, Five-Finger ), 



Rosacece. 



Seeds, layers, division, green cuttings. 

 Poterium, including Sanguisorba (Burnet). Rosaces. 



The herbaceous kinds are increased by seeds and divi- 

 sion. The shrubs are raised from soft cuttings, under 

 glass. See Burnet. 



Prickly Ash. See Zanthoxylum. 



Prickly Pear. See Opuntia. 



Pride of India. See Melia. 



Prim. See Ligustrum. 



Primula, Polyanthus (Primrose, Cowslip). Primulacece. 



Seeds, sown carefully in very fine soil, under glass. 

 The seeds should be fresh ; old ones often lie dormant a 

 year. Many sorts are increased by division. See 

 Auricula. 



Prinos. See Ilex. 



Pritchardia. Palmacea. 

 Increased by seeds. 



Privet. See Ligustrum. 



Prune. See Plum. 



Prunus, Amygdalus. Rosacece. 



The dwarf almonds (Amygdalus} are increased by 

 seeds, division, cuttings, and by budding upon seedling 

 plum or peach stocks ; also by root cuttings. Peach 

 stocks give larger trees at first than plum stocks, but the 

 trees are not so long-lived. Perhaps ten years may be 

 considered the average life of most ornamental almonds 

 upon the peach, while upon the plum they may persist 

 twenty-five years or more. (See Almond. ) The ornamen- 

 tal cherries, peaches, etc., are propagated in essentially the 

 same manner as the fruit-bearing varieties. P. Lauro- 

 Cerasus and P. Lusitanica, the cherry laurel and Portugal 

 laurel, may be propagated by short cuttings of ripened 

 wood, in a cool greenhouse in autumn. P. Pissardii prop- 

 agates by cuttings of the soft wood and, with more diffi- 

 culty, from cuttings of dormant wood. Soft cuttings suc- 

 ceed well with many of the double-flowering plums and 

 cherries, if the wood is grown under glass. See Apricot, 

 Cherry, Peach, Plum. 



