POTENTILLA — PRUNUS. 305 



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

 Rosacea. 

 Seeds, layers, division, green cuttings. 

 Poterium, including Sanguisorba (Burnet). Rosacea. 



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 I<igustrum. 



Primula, Polyanthus (Primrose, Cowslip). Pri-mulacea. 

 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. Palmacees. 

 Increased by seeds. 



Privet. See Ligustrum. 



Prune. See Plum. 



Prunus, Amygdalus. Rosacea. 



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, 



