AMENTIFER^. 197 



Yar. a is a tree usually of moderate size, though sometimes attaining 

 a great height, with smooth grey bark ; suckers numerous ; the leaves 

 2 to G inches long, exceeding the petiole, with much stiifer hairs on 

 the underside than in P. canescens. Mature leaves on long much com- 

 pressed petioles ; lamina 1 to 2 inches long by 1 to 3 inches broad, much 

 resembling that of P. canescens, but more regularly and less deeply 

 sinuate-serrate, the teeth curving inwards and rounded off at the apex. 

 The young leaves have a few hairs above, but are quite silky and 

 white beneath; they at length become quite glabrous on both sides. 

 Female catkins longer and with more deeply laciniate scales than in 

 P. canescens. Segments of the stigma shorter and thicker, generally 

 4, rarely 6 or 8. Fruit considerably smaller and narrower. Leaf- 

 buds more pointed and with scarcely any hairs except at the margins 

 of the scales. 



Yar. 3, at least the specimens of it I have seen, is a bush 3 to 12 

 feet high, "with the leaves smaller, somewhat inclining to rhombic, and 

 the teeth usually curving less forward, often so little as to be rather 

 dentate than serrate, though this varies much in both forms. 



Aspe7i. 



French, Peuplier tremhle. German, Zitterpappel. 



The origin of the popular name, Aspen, is thns given by Dr. Prior : "In Chaucer 

 aspe, the adjective form of which we have adopted as the name of the tree : Anglo- 

 Saxon, aejpse, and German aspe, words that seem to represent the sibilant sound of 

 its ever-moving leaves, as in asp, Greek aanig, a serpent, from its hissing ; whisper, 

 wasp, and sibilo. Skinner would derive it from the Gi'eek aairuipu), palpitate, but 

 the word is much older in the north than the studj of Greek." The peculiar 

 trembling movement of the leaves of the aspen has given rise to much speculation, 

 and various traditions. It is accounted for by mechanical facts, and the flattened 

 petiole of the leaves allows the slightest motion of the atmosphere to afiect the leaf, 

 so that — 



" When zephyrs wake. 

 The aspen's trembling leaves must shake," 



and, by their friction on one another, make a constant rustling sound. This trembling 

 is constantly the subject of poetical allusions. In Scotland there is a superstition 

 that the cross of Christ was made from the wood of this tree, and that consequently 

 it never ceases to tremble, as a consequence of the terrible event in which its species 

 became involved. A recent writer observes that this can hardly apply to the leaves, 

 as the cross could not have been made of them ; but perhaps, she adds, "they struggle 

 to escape from the wicked wood on which they grow." Gerard says, " It is the 

 matter whereof women's tongues were made (as poets and others report), which 

 seldome cease wagging." This sentiment is surely somewhat malicious. 



In its natural state, the trembhng poplar forms the chief food of beavers, where 

 the animal abounds ; and deer, goats, and other creatures, are fonder of the spray 

 and buds than those of any other tree. The wood is white and tender, and is 

 employed by turners, by sculptors, and engravers. The bark is used in tanning, in 

 common with that of the other species. As fuel, it is inferior, and gives but little 

 heat. Its charcoal is light and soft, and is used in making gunpowder. The leaves, 



