trees in England, two distinct forms are apparent. Certain trees have pubescent branchlets and bear large cones, up to two inches in length, which have large scales purplish in colour before ripening, long exserted bracts and long-winged seeds. Other trees with glabrous branchlets bear small cones, about 14 inch in length, with scales green before ripening, shorter exserted bracts and small seeds with short wings. The former trees are more narrowly pyramidal in habit.
History
This splendid tree is the largest of the genus, and though it has been known to botanists for many years, it was till quite recently, on account of its being neglected by the early explorers of the limited region which it inhabits, one of the rarest exotic conifers in cultivation.
It was first discovered by David Douglas’ in 1826 near Fort Colville on the Upper Columbia river; but was mistaken by him for the European larch. His specimens in the Kew Herbarium are labelled "in aqueous flats on the mountain valleys near Kettle Falls and in the Rocky Mountains, 1826.” The tree was first described in 1849 by Nuttall, who found it on the Blue Mountains of Oregon in 1834.
It was introduced into cultivation in the Arnold Arboretum in 1881, seed- lings having been imported from Oregon; but in the climate of New England these have remained small and stunted, though branches grafted on the Japanese larch have grown vigorously. Forty plants were sent from the Arnold Arboretum to Kew in 1881, and one tree survives (the fate of the other plants being unknown), which is remarkable for its beautiful straight stem and narrow, almost columnar habit. This tree bears large purplish cones, and is now (1906) 33 feet in height and 17 inches in girth.
Ten plants were subsequently sent in 1889 from the Arnold Arboretum to Kew, of which two survive. One of these trees is, however, identical in cones and pubescent branchlets with the tree of 1881, and may be erroneously labelled 1889 ; it has suffered damage at the top. The other tree, which has glabrous branchlets and bears small green cones, is not quite so narrow in habit, and measured in 1906 29 feet in height and 17½ inches in girth.
The only other large tree in Britain with which we are acquainted is growing at Grayswood Hill, Haslemere; and measured in 1906 28 feet high by 19 inches in girth. It has pubescent branchlets, and bears purple cones, which are, however, smaller than those of the Kew tree, labelled 1881. Mr. Chambers informs us that this tree was obtained from Messrs. Dickson of Chester in 1889.
Distribution
The western larch is confined to the more humid parts of the region, which extends from the western slope of the Rocky Mountains in British Columbia and
1 Comp. Bot. Mag. ii. 109 (1830), where Douglas states that he measured trees 30 feet in girth.
