76 



8ILVA OF NORTE AMERICA. 



CONIFERjE. 



associates in the forests of northwestern America in the graceful sweep of its long and drooping 

 branches and in its delicate lustrous foliage. Introduced into cultivation in 1851 by John Jeffrey/ 

 Tsuga heterophylla flourishes in the gardens of temperate Europe, where it has grown rapidly, and 

 where, with long lower branches resting on the ground, slender drooping branchlets, and pendent 

 leading shoots, it well displays the beauties of its vigorous youth.^ 



The bark is thin, of a dark color, much divided in small longitudi- 

 nal interstices ; the bark of the boughs and young trees is some- 

 what smooth, but not equal (in this respect) to the balsam-fir ; the 

 wood is white, very soft, but difficult to rive ; the trunk is a sim- 

 ple, branching, and diffuse stem, not so proliferous as pines and 

 firs usually are. It puts forth buds from the sides of the small 

 boughs, as well as from their extremities, the stem terminates, like 

 the cedar, in a slender pointed top. The leaves are petiolate ; the 

 foot-stalks short, acerose, rather more than half a line in width, and 

 very unequal in length; the greatest length seldom exceeds one 

 inch, while other leaves, intermixed on every part of the bough, do 

 not exceed a quarter of an inch. The leaf has a small longitudinal 

 channel on the upper disk, which is of a deep and glossy green, 

 while the under disk is of a whitish green. It yields but little rosin. 

 What is remarkable, the cone is not longer than the end of a man's 



thumb ; it is soft, flexible, of an ovate form, and produced at the 

 ends of the small twigs." (Ed. Coues, iii. 830.) 



There is no other tree in the forests of Pacific North America 

 but this Hemlock to which this description can be applied, and 

 there seems to be no other course but to adopt Kafinesque's specific 

 name and call the western Hemlock Tsuga heterophylla and Pat- 

 ton's Spruce Tsuga Mertensiana, although such a change of names 

 will certainly prove highly confusing. 



^ See xi. 41. 



2 See Fowler, Gard. Chron. 1872, 75 (as Abies Alhertiana). — 

 Dunn, Jour. R, Hist. Soc. xiv. 78 (as Abies Albertiand). 



In the eastern United States Tsuga heterophylla has not yet 

 shown its ability to endure the hot dry summers or the changes of 

 our uncertain winter climate, and rarely survives here more than 

 a few years. 



EXPLAISTATION OF THE PLATE. 



Plate DCV. Tsuga heterophylla. 



1. A branch with staminate flowers, natural size. 



2. A staminate flower, enlarged. 



3. An anther, front view, enlarged. 



4. An anther, side view, enlarged. 



5. A branch with pistillate flowers, natural size. 



6. A pistillate flower, enlarged. 



7. A scale of a pistillate flower, upper side, with its ovules, enlarged, 



8. A pistillate flower, lower side, with its bract, enlarged. 



9. A fruiting branch, natural size. 



10. A cone-scale, lower side, with its bract, natural size. 



11. A cone-scale, lower side, with its bract, natural size. 



12. A cone-scale, upper side, with its seeds, natural size. 



13. Seeds, enlarged. 



r 



14. Vertical section of a seed, enlarged. 



15. An embryo, enlarged. 



16. Cross section of a leaf, magnified fifteen diameters. 



17. "Winter branch-buds, enlarged. 



18. Seedling plants, natural size. 



