TSUGA 



TSUGA 



3391 



tary resin-duct situated in the middle of the If. below 

 the fibro- vascular bundle. The light, soft, brittle and 

 coarse-grained wood is not durable and not much valued 

 except that of T. heterophylla, which is harder and more 

 durable, and that of T. Sieboldii, which is esteemed in 

 Japan for its durability. The bark is rich in tannin and 

 that of T. canadensis is extensively used for tanning 



3858. Tsuga Sieboldii. (XH) 



leather. T. canadensis should be called "hemlock 

 spruce," but in common speech it is usually alluded to 

 as "hemlock." The "hemlock" of the ancients is a 

 poisonous umbelliferous herb described in this work as 

 Conium maculatum. 



The hemlock spruces are evergreen trees of pyramidal 

 habit, with spreading irregularly whorled much rami- 

 fied branches clothed with small linear usually two- 

 ranked leaves and small cones which are usually freely 

 produced. The cones are only about 1 inch long except 

 in one species, which has cones two or three times as 

 large. T. canadensis is quite hardy North and the 

 Japanese species and T. caroliniana have proved hardy 

 as far north as Ontario. T. Mertensiana is almost as 

 hardy. T. heterophylla is tenderer. There are probably 

 no more beautiful hardy conifers than the hemlocks, 

 and they must be ranked among the most ornamental 

 and useful trees for park planting. They do not have 

 the stiff formal appearance of many of the conifers, 

 but are graceful and stately at the same time. T. 

 heterophylla is the most vigorous species and is more 

 graceful than the Canadian hemlock, but tenderer. T. 

 Mertensiana is noticeable for its light bluish green foliage 

 and the more narrow pyramidal habit. T. Sieboldii is a 

 very handsome species with dark green glossy foliage, 

 but of slow growth and in cultivation usually remains 

 shrubbv. T. canadensis bears pruning well and is well 

 suited for tall hedges (see Gng. 2:289. Gn. M. 2:15; 

 4:19). The other species will probably bear pruning 

 equally well. The hemlocks are not very particular as 

 to the soil, provided it contains a sufficient amount of 

 constant moisture. Tsugas are not difficult to trans- 

 plant. Propagation is by seeds sown in spring and by 

 grafting on T. canadensis. The varieties and the 

 Japanese species are also raised from cuttings. See also 

 Arboriculture, Abies, and Picea for cultivation. 



INDEX. 



B. Margin of Ins. entire; apex of Ins. 

 usually emarginate, sometimes ob- 

 tuse. 



c. Scales of cones suborbicular. 

 D. Branchlets yellowish brown, gla- 

 brous 1. Sieboldii 



DD. Branchlets reddish brown, -pu- 

 bescent 2. diversifolia 



cc. Scales of cones oblong: Its. often 



obtuse 3. caroliniana 



BB. Margin of Ins. finely denticulate, at 

 least toward the apex; apex of Irs. 

 obtuse or acutish. 

 c. Cones peduncled; scales almost 



orbicular, glabrous 4. canadensis 



cc. Cones sessile; scales oval, slightly 



puberulous outside 5. heterophylla 



AA. Lns. stomatiferous on both sides, flat or, 

 convex above, spirally arranged: cones 

 2-3 in. long ( Hesperopeuce) 6. Mertensiana 



1. Sieboldii, Carr. (T. Araragi, Koehne). Fig. 3858. 

 Tree, attaining 100 ft., with spreading slender branches: 

 branchlets pale yellowish brown, somewhat glossy, gla- 

 brous, with reddish If .-cushions: Ivs. linear, usually 

 broadest at the apex, emarginate, grooved and glossy 

 dark green above, with 2 whitish lines beneath, K~M m - 

 long: cone ovate, 1-1 M in. long, the peduncle exceeding 

 the bud-scales: bracts bifid. Japan. G.F. 10:492 (adap- 

 ted in Fig. 3858). F.E. 32:1301. S.I.F. 2:4. 



2. diversifdlia, Mast. (Abies diversifolia, Maxim. 

 T. Sieboldii nana, Carr.). Fig. 3859. Tree, very similar 

 to the preceding, but smaller and chiefly distinguished 

 by the reddish brown pubescent branches: Ivs. linear, 

 emarginate or obtuse, shorter and narrower, broadest 

 at the middle or toward the base: cone smaller, J^-%in. 

 long: peduncle not exceeding the bud-scales; bracts 

 truncate, crenulate, not or slightly bifid. Japan. G.F. 

 6:495; 10:493 (adapted in Fig. 3859). S.I.F. 2:4. 



3. caroliniana, Engelm. CAROLINA HEMLOCK. Tree, 

 attaining 70 ft., of more compact habit and with darker 

 green foliage than the following: young branchlets 

 light reddish brown, finely pubescent or almost- gla- 

 brous: Ivs. linear, obtuse or emarginate, dark green 

 and glossy above, with 2 whitish lines beneath, J^-%in. 

 long: cones oblong, 1-1 % in. long, peduncled; scales 

 oblong. Va. to S. C. S.S. 10:604. G.C. II. 26:780. 

 G.P. 2:269. Gn.M. 12:214. More graceful than the 

 following. 



4. canadensis, Carr. (Abies canadensis, Michx.). 

 COMMON HEMLOCK. Fig. 3860. Tree, attaining 70 and 



KEY TO THE SPECIES. 



A. LTS. with 2 white lines beneath, 

 grooved above, much flattened, dis- 

 tinctly 2-ranked: cones Y^-lYi in. 

 long. 



3859. Tsuga diversifolia. 



occasionally 100 ft. : young branchlets yellowish brown, 

 pubescent: Ivs. linear, obtuse or acutish, dark green 

 and obscurely grooved above, with 2 whitish lines 

 beneath, %-%ui. long: cones ovoid, J-%in. long, 

 peduncled; scales almost orbicular. New Bruns. and 

 Wis., south to Ala. S.S. 10:603. G.C. III. 48:350. 

 Gn.M. 12:215. J.H. III. 66:467. G.W: 1, p. 359; 5, p. 

 536; 9, p. 213. The hemlock spruce yields the lumber 



