112 TREES AND SHRUBS 



sometimes difficult to obtain, germinate freely and 

 quickly. 



TsuGA. — The Hemlock Spruces are easily and 

 quickly obtained from seeds, and one or two will 

 strike from cuttings ; the varieties do best when 

 grafted on the species they belong to, though T. 

 pattoniana var, glauca, more commonly known as 

 Abies hookeriana, will come fairly true from seed, 

 about 75 per cent, being the usual quantity if the 

 seed is obtained from good plants. 



PiCEA. — This genus has been mentioned before 

 as being commonly grafted on P. excelsa (the 

 Common Spruce), which is an easy way of obtain- 

 ing young plants, which, however, cannot be recom- 

 mended to form good specimens in after years. 

 The species of Picea should all be raised from seed, 

 and the many named varieties of P. excelsa should be 

 grafted on the parent species. At least one-half the 

 plants of P. Engelmanni var. glauca and P- pungens var. 

 glauca (the Californian Blue Spruce) will be found 

 true to name when raised from seeds, while their 

 superiority afterwards over grafted plants is evident. 



Cedrus, Larix, and Pseudolarix. — It should 

 always be remembered that these three are quite 

 distinct genera, and for purposes of propagation 

 should never be used in conjunction with each 

 other, the first being evergreen and the two latter 

 deciduous. The species of all three should be 

 raised from seed ; the varieties of Cedrus should 

 be grafted on that genus, the forms of Larix on the 

 Larch, though the geographical forms of the Common 



