This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Evergreen shrubs or trees with scale-like sickle shaped ap-pressed imbricate leaves, monoecious flowers, and globular cones. Scales of the fruit woody, overlapping, with about 5 winged seeds at the base of each. A Japanese genus of recent introduction, including some of the most curious and beautiful members of this order. The name is from Thuja and resemblance. For Th. borealis, see Cupressus Nutkaensis.
1. Th. dolabrata. - This was the first species introduced, and as a small shrub it stands almost unrivalled in the rich verdure of its glossy hatchet-shaped leaves and peculiar growth. In Japan it is said to form a most splendid tree of large size, and from its apparent hardiness we may look for it to do well with us, though it is not of very rapid growth. The leaves are somewhat loosely imbricated and more or less silvery on the under surface or shady side. But it is perhaps the habit of this plant that constitutes its most striking feature. The main branches are few and rather loose and spreading, with numerous compressed pendulous branchlets, and it does not readily form a distinct leader, or rather the leader does not appear distinctly above the lateral branches. It appears to prefer a moist cool soil. There is a variety in which the foliage is prettily variegated with pale yellow, and another, called nana, of very dwarf habit.
2. Th. laetevirens. - A small shrub about 4 or 5 feet high, with slender foliage resembling that of a Lycopod. It is described as an exquisitely beautiful hardy shrub, but it is still very rare in this country except as a very small plant.
3. Th. Standishii. - This approaches Th. dolabrata, and may be nothing more than a distinct variety of that species. The branches are more pendulous in this, and the foliage smaller, glaucous, not silvery beneath.
These are probably garden varieties of Th. dolabrata, but they are sufficiently distinct to be desirable.