170 THROUGH GLADE AND MEAD, 
beset it around. The yarrow now seen by the road- 
side and that gathered on the summit of Mount Wash- 
ington on that August day are closely linked together 
in my thought as an illustration of the capacity some 
plants have of adapting themselves to a new environ- 
ment. 
Near the railroad crossing on the road from Mill- 
bury to Wilkinsonville is the one place where I have 
found our one representative of the order Rutacez, most 
of which are natives of South America and the temper- 
ate climes of other lands. This is the northern prickly 
ash, not at all connected, except in name, with our other 
ash-trees. Its branches are covered with strong, sharp 
prickles, arranged in no definite order, and the leaves 
are pinnate. The bark is bitter, aromatic and stimulant, 
sometimes used to alleviate the toothache; from which 
fact it is sometimes called toothache-tree. 
The shagbark or shellbark hickory is easily the 
chief of all the trees in our list. The genus is an ex- 
clusively North American one. The uses to which its 
wood is put are very numerous. As fuel, it stands at 
the head of all trees in our climate. It is the heaviest 
of our native woods and yields, cord for cord, more 
heat than any other, in any shape in which it may be 
consumed. Its specific gravity is .8372; its relative 
approximate fuel value is .8311. It is worthy of culti- 
vation for its nuts alone. 
