Tsuga 



^39 



TSUGA CANADENSIS. Hemlock or Hemlock Spruce 



Tsuga canadensis, Carrifere, Traits Conif. 189 (1855); Sargent, Silva N. Amer. xii. 63, t. 603 (1898), 

 and Trees N. Amer. 48 (1905); Kent, Veitch's Man. Conifera, 463 (1900). 



Pinus canadensis, Linnaeus, Sp. PL 1421 (1763); Lambert, Genus Pinus, i. t. 32 (1803). 



Abies canadensis, Michaux, Fl. Bor. Am. ii. 206 (1803), and Hist. Arb. Amer. i. 137, t. 13 (1810); 

 Loudon, Arb. et Frut. Brit. iv. 2322 (1838). 



Picea canadensis. Link, Linnaa, xv. 523 (1841). 



A tree attaining in America over 100 feet in height, but usually only 60 to 

 70 feet, with a girth of 12 feet as a maximum. Bark of old trees brownish and 

 deeply divided into narrow rounded ridges, covered with appressed scales. 



Young shoots greyish in colour and covered with short stiff pubescence. Leaves 

 pectinately arranged, the shorter ones on the upper side of the shoot ; those on the 

 median line above pointing forwards, appressed to the twig, and displaying their 

 white under surfaces. They are ^ to f inch long, linear, usually broadest towards the 

 base and tapering to the apex, which is rounded or acute ; distinctly and sharply 

 serrulate in margin ; dark green above with a median groove often not continued to 

 the apex ; lower surface with distinct midrib and two narrow well-defined white 

 stomatic bands, the edges being pure green in colour. Buds brown, ovoid, pointed ; 

 scales ciliate, pubescent, keeled, acute. 



Cones, i to f inch long, ovoid, on slender puberulous stalks nearly \ inch long, 

 composed of five series of scales, with about five scales in each series. Scales orbicular 

 oblong, nearly as broad as long, entire and slightly bevelled in margin, striate, 

 glabrescent in the exposed part. Bract small, concealed, lozenge-shaped. Seed 

 with an oblong wing, decurrent half-way on its outer side. The seed with wing 

 about two-thirds the length of the scale. 



Varieties 



A considerable number of horticultural varieties are known, no less than 

 fourteen being described by Beissner. Some of these are variegated forms, as var. 

 argentea or albo-spica, in which the tips of the young shoots are whitish. Others 

 differ in habit and stature, as var. pendula, with pendulous branches, and var. 

 Sargentii^ a flat-topped bushy form of compact habit with short pendulous branches. 

 The latter was found about forty years ago on the Fishkill Mountains in New York, 

 and was first cultivated and made known by Mr. H. W. Sargent. One of the 

 original plants, growing on the Howland estate, in Matteawan, New York, is now 

 about 25 feet across. Grafted plants of this variety form in a few years an erect 

 stem, and lose the dense low habit which is the charm of the original seedlings.^ 



Var. parvifolia, as cultivated at Kew, is a shrub, with stout branchlets, and very 

 short leaves, about \ inch long, which spread radially outwards from the shoot. 



(A. H.) 



* Sargent, Garden and Forest, x. 490 (1897). 



