Populus 1837 



petiole ; the capsules are also very pubescent. Specimens from Oregon, Washing- 

 ton, and British Columbia have usually larger leaves, much longer than broad, 

 distinctly acuminate, and with less pubescence ; and their capsules are sometimes 

 nearly glabrous. The latter form, which is the one in cultivation, is considered by 

 Dode {pp. cit. 64) to be a distinct species, P. hastata ; and may, on further investiga- 

 tion in the field, turn out to be worth ranking as a distinct variety, P. trichocarpa, 

 var. hastata. Jepson also mentions a form ingrata from San Bernardino county, 

 which has small lanceolate leaves.^ 



This magnificent poplar, the largest of the genus, is a native of the Pacific 

 coast region of North America from southern Alaska to San Diego county in 

 California, extending inland in British Columbia as far as the valley of the Columbia 

 river, and in California to the western slope of the Sierra Nevada. It is reported to 

 occur in eastern Washington ^ and in western Montana ; ^ but the balsam poplar in 

 these regions is possibly P. balsamifera. P. trichocarpa grows mainly in open groves 

 in river valleys, attaining its largest size near sea-level in the coast region north of 

 California ; southward, it is a small tree rarely more than 40 ft. high,* ascending to 

 6000 ft. altitude in the Sierra Nevada in central California. It is most abundant^ in 

 Oregon and Washington, where its timber is used for making staves and wooden 

 ware. Jepson states that the wood is light, soft, and fairly close-grained, but not 

 strong. (A. H.) 



It is the largest deciduous tree ® of the Pacific coast region, attaining its greatest 

 size on Puget Sound, where it is sometimes 200 ft. in height and 6 to 8 ft. in diameter. 

 I saw it in perfection on a farm in Vancouver Island called Swallowfield, some 

 miles north of Duncans, and measured the tree here figured (Plate 388), which was 

 growing in a meadow on rich alluvial soil, and was at least 140 ft. high with a bole 

 70 ft. long and 28 ft. 3 in. in girth. Another tree, with the top broken, had a bole 

 80 ft. by 21 ft. 3 in. which I estimated to contain 1300 to 1400 ft. of timber ; and on 

 8th June it was covered with seed capsules which I gathered, but being unable to sow 

 them till I came home, failed to raise any trees. A beautiful picture of a group of 

 these trees on the banks of the Merced river in the Yosemite valley is given in 

 Garden and Forest, v. 281. 



This species is of recent introduction '' in England, the oldest specimen known to 

 us being a tree in the Edinburgh Botanic Garden, which was planted in 1892, and 

 measured in 1906, 39 ft. by 2 ft. 6 in. Another at Grayswood, planted in 1898, 

 measured in 1906, 32 ft. by 2 ft. i in. The largest specimen at Kew was obtained 

 from Spath in 1896, and measured 55 ft. by 3 ft. 10 in. in 191 1. 



1 Var. cupulata, Watson, m Amer. Joum. Science, cxv. 136 (1878), was a name given to a specimen from Plumas 

 County, California, with flowers, in which the disc was campanulate and pubescent. 



2 Piper in Cont. U.S. Nat. Herb. xi. 217 (1906). 



3 M. E. Jones, Montana Botany Notes, 24 (1910). 



'' Hilyard, Soils, 480(1 906), says that this species tolerates white alkaline soil, containing sodium sulphate and chloride ; 

 but remains dwarf and stunted on black alkaline soil, containing sodium carbonate. 

 5 Jepson, op. cit. 



^ Dawson, Cat. Can. Plants, i. 457 (1884), states that there is some difficulty in separating this tree from P. balsami- 

 fera in the northern and north-eastern part of British Columbia, and perhaps the tree of the Yukon valley, which he refers to 

 P. balsamifera, is the same which Sargent considers P. trichocarpa. 



' Dieck, Netih. Offert. Zoschen, 1889-1890, p. 13, introduced it on the Continent from British Columbia in 1889. 

 VII 2 B 



