TSUGA CANADENSIS, Hemlock or Hemlock Spruce
- Tsuga canadensis, Carrière, Traité Conif. 189 (1855); Sargent, Silva N. Amer. xii. 63, t. 603 (1898), and Trees N. Amer. 48 (1905); Kent, Veitch’s Man. Coniferæ, 463 (1900).
- Pinus canadensis, Linnæus, 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, Linnæa, 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 ⅓ to ⅔ 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, ½ to ¾ inch long, ovoid, on slender puberulous stalks nearly ¼ 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 4 inch long, which spread radially outwards from the shoot. (A.H.)
1 Sargent, Garden and Forest, x. 490 (1897).
