508 A HANDBOOK OF CONIFERS 



brown, sapwood lighter. The timber is cut into thin boards 

 for the Hnings of walls and ceilings, sliding doors, boxes and bent 

 woodwork. It is not, however, plentiful enough to possess 

 much commercial value. 



T. japonica succeeds in the British Isles under similar con- 

 ditions to T. plicata, but is a less vigorous tree, being apparently 

 of slow growth. Its yellowish green foliage makes it a useful 

 plant for positions where the more sombre hues of darker-leaved 

 evergreens would be out of place. 



Thuya koraiensis, Nakai. 



Thuya kongoensis, Nakai. 



This recently introduced species varies in habit from a low or 

 trailing shrub to a slender, graceful, narrow-pyramidal tree. It 

 is alUed to the Japanese T. japonica, from which it appears to 

 differ by its coarser foUage, which is wholly glaucous on the 

 under-surface. ^ The cones are said to be broader than in the 

 Japanese species and the cone-scales thicker. 



It is a native of Corea and small plants are in cultivation at 

 Kew. 



Wilson in Journ. Arnold Arb. i, 186 (1920). 



Thuya occidentalis, Linnaeus. (Fig. 111.) 

 American Arbor- vit^. 



Thuya obtusa, Moench ; T. odorata, Marshall ; T. sibirica, Hort. 

 Cupressus Arbor-vitse, Targ. Tozz. Arbor- vitae ; Northern White Cedar ; 

 White Cedar. 



A tree 50-60 ft. high and usually 4-9 ft. but occasionally 18 ft. 

 in girth, the trunk often forked from near the ground and 

 prominently buttressed. Bark ^| in. thick, reddish brown or 

 orange-brown, and fissured into narrow ridges, the thin outer 

 bark scaling off in small rolls. Branches horizontal, turning 

 upwards at the ends ; branchlets much divided, the lateral ones 

 small. Leaves dark green above, pale green below, emitting a 

 tansy -hke odour when bruised ; those on leading shoots about 

 ^ in. long, sharp-pointed, rounded on the back, with conspicuous 

 resin glands ; those on lateral shoots smaller, about yV in. long, 

 rounded or bluntly pointed with the glands very small or absent. 

 Cones oblong, ^| in. long, yellowish and erect when young, 

 brown and pendent when mature at the end of the first summer ; 

 scales in 4-5 pairs, the second and third pairs larger than the 

 others and fertile ; thin, leathery, the apex a short triangular 

 point, the thickened process within less pronounced than in T. 

 plicata. Seeds | in. long with thin marginal wings. 



A large number of forms have been given varietal names. 



^ The lower half only of the under-surface of leaves of T, japonica is glaucous. 



