266 SELECT PLANTS FOR INDUSTRIAL CULTURE 



Penny-royal and Spearmint. It likes to grow on rocky wood- 

 land, and on such it might be easily naturalised. 



Pycnanthemum montanum, Michaux. 



The Mountain Mint of North America. A perennial herb of 

 pleasant, aromatic, mint-like taste. These two particular 

 species have been chosen from scYeral North American kinds 

 to demonstrate that we may add by their introduction to the 

 variety of our odorous garden-herbs. They may also be 

 subjected with advantage to distillation. 



Pyrularia edulis, Meissner. 



Nepal, Khasia, Sikkim. A large umbrageous tree. The 

 drupaceous fruit is used by the inhabitants for food. A few 

 other species occur in Upper India, one on the high mountains 

 of Ceylon and one in North America. The latter, P. pubera 

 (Mich.) , can be utilised for the oil of its nuts. 



Pyrus coronaria, Linne. 



The Crab Apple of North America. This showy species is 

 mentioned here as worthy of trial culture, since it is likely 

 that it would serve well as stock for grafting. Best grown in 

 glades. Wood nearly as *tough for screw-work as that of the 

 Pear Tree (Eobb) . It seems unnecessary to refer here to any 

 of the forms of Pyrus communis (L.), P. Mains (L.), P. 

 Cydorda (L.), and P. Germanica (J. Hooker), (MespUus 

 Germanica, L.), but it may passingly be observed that curious 

 fruits have been produced lattei'ly in North America in the 

 hybridisation of the Apple with the Pear. Pearwood is one 

 of the best substitutes for boxwood in xylography. Pyrus 

 communis attains an age of over 300 years, fully bearing. 

 Trees are known to have attained a circumference of 10 

 feet at 3 feet from the ground. At Garmouth a tree over 100 

 years old has borne up to 26,800 fruits annually, and in some 

 years more. The circumference of its frond is 126 feet 

 (Masters) . A bitter glycosid — namely, Phlorrhizin — is obtain- 

 able from the bark of apple and pear trees, particularly from 

 that of the root ; while a volatile alkaloid — namely, trimethy- 

 lamin — can be prepared from the flowers. 



Pyrus Japonica, Thunberg. 



Japan. One of the prettiest of small hedge-bushes. Under 

 favourable circumstances it will produce its quince-like fruit. 



Pyrus nivalis, Jacquin. 



The Snow Pear. Middle and South Europe. This would be 



