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.
Handsome evergreen trees with imbricated scale-like leaves and monoecious flowers. Fruit oval, consisting of 4 leathery or ligneous valvate unequal scales. Seeds winged, 1 or 2 at the base of each scale. Species few, from New Zealand and Southwestern and North-Western America. The name is from libanos, incense, and cedrus, the cedar, in allusion to the odoriferous wood.
1. L. decurrens, syn. Thuja Craigiana or Corrigiana and Th. gigantea of English gardens. - This is a very beautiful and distinct evergreen tree of compact erect habit, with a remarkably stout trunk. It is generally known under the latter name, but unless this genus be merged in Thuja, this is its proper position, on account of the difference in its fruit from that of the true Arbor-Vitses. The branchlets are numerous, alternate, and plaited, or flattened laterally. Leaves bright rich glossy green, small linear and scale-like, quadrifariously imbricated, acute at the free apex, with long decurrent base, persistent and elongated on the older branches. The glandless decurrent leaves and columnar habit readily distinguish this from all its allies. Fruit ovate or oblong, erect, smooth. Scales furnished with a small recurved prickle just below the apex. A native of the Sierra Nevada Mountains of California, where it attains a height of 120 to 140 feet.
2. L. Chilensis. - A handsome tree, growing 60 to 80 feet high in its native country. Branches compressed, spreading and pendulous. Leaves oblong-trigonous, appressed, obtuse, glaucous green. Fruit ovate, composed of four woody scales. This ornamental species is a native of the Andes of Chili, and rather tender in this country.
3. L. tetrdgona. - This is also a South American species, extending from Valdivia to Magellan's Straits, and ranging according to locality from a dwarf bush to a lofty tree 120 feet or more in height. With us it is a shrub of compact pyramidal growth, with spreading depressed branches. Branchlets tetragonal, densely clothed with small ovate scale-like obtuse pale green leaves, imbricated in four rows. Fruit consisting of 6 coriaceous scales in three pairs. This is a somewhat hardier species than the last.
L. Doniana is an exceedingly beautiful species from New Zealand, but it will not bear our Winters.