Populus 1833 



p. Michauxi has slightly pubescent branchlets and leaves which have occasionally a 

 subcordate base, and is intermediate between the two species ; but it has the narrow 

 leaves of P. balsamifera, and cannot be confused with P. candicans, which has broadly 

 ovate deeply cordate leaves, (A, H.) 



P. balsamifera is confined to North America, where it is known as Balsam or 

 Tacamahac, and ranges from far north in Alaska and Canada southwards to 

 northern New England, New York, central Michigan and Minnesota, the Black 

 Hills of Dakota, north-western Nebraska, northern Montana, Idaho, Oregon, and 

 Nevada. It is the largest of sub-arctic American trees,^ attaining its greatest size 

 on the Peace river and other tributaries of the Mackenzie river, where, according 

 to Macoun, it is often nearly 150 ft, high, with a trunk occasionally over 7 ft, in 

 diameter and free of branches from 60 to 100 ft. up. It is the characteristic tree 

 along the streams in the prairie regions of British America, and is common 

 throughout the northern border of the United States, growing on alluvial lands 

 liable to floods and on the borders of swamps. 



According to Aiton it was cultivated at Hampton Court in 1692, and was again 

 introduced in 1731, when a tree given by Queen Caroline to Sir Hans Sloane was 

 planted in the Chelsea Botanic Garden. It was introduced^ into Scotland in 1768 

 by seeds sent from Canada. We have seen no pistillate trees of this species, which 

 has become exceedingly scarce in cultivation, being now almost entirely supplanted 

 by P. candicans, the balsam poplar usually grown by nurserymen in England. It 

 differs from P. candicans in habit, being a narrower tree with ascending branches, 

 and seems to be short-lived in our climate, which is perhaps too warm ^ for it. 



The largest tree which we have seen in England is one (Plate 387) at Bute 

 House, Petersham, which in 1905 was 71 ft, high by 7 ft. 10 in., and surrounded by 

 a great number of suckers. The leaves of the suckers, as in other species of 

 poplars, attain a large size, occasionally 6 to 8 inches in length. At Kew there are 

 two small trees, obtained from Spath in 1905. At Syston Park, Lincolnshire, there 

 was a tree of considerable size, growing on an island in the lake, which was cut 

 down thirty years ago; but numerous suckers remain, about 18 ft. high, which 

 produce flowers abundantly. A younger tree at Belton, 20 ft. high, planted fifteen 

 years ago, produced staminate flowers, which were drawn by Miss F. H. Woolward. 

 A tree at New Humberstone, Leicester, of which specimens in flower were collected 

 by Mr. H. Burbank, was 50 ft. by 5 ft, 3 in. in 1905. It has since been topped. 



In Scotland there is a large tree in the park at Castle Menzies, which looks 

 older than any other I have seen, and in 1907 measured 68 ft. by 11 ft. 10 in. 

 Another very old -looking tree grows by the schoolhouse at Achnacarry, and 

 has bark more like that of an ash than a poplar. It measured in June 1910 about 

 60 ft. by 7 ft. I also saw several good-sized trees in Glen Urquhart, 



' E. T. Seton, Arctic Prairies, 330 (1912), says : " The balsam poplar attains a large size on the lower Athabasca and 

 the Slave rivers, at least 100 ft. We observed it as far as the eastern extremity of Great Slave Lake, but there it is scarcely 

 more than a shrub. The leaves had partly turned colour near Caribou island on September 22." 



2 Walker, Essays Nat. Hist. 65 (1812). 



3 Britton and Shafer, N. Amer. Trees, 172 (1908), state that this poplar is not much planted south of its natural range in 

 America, as it does not well endure hot summers. 



