They are still worrying in the Old World about the identity of various trees which they have growing under the names of Thuja Lobbii, T. Menziesii, T. plicata, T. Standishii, T. Craigiana, and T. gigantea, and Libocedrus decurrens. Americans have long ago simplified the matter by dropping all the names except those originally given by the first describes. The Western Arbor Vitse is therefore simply Thuja gigantea, and the other in dispute, the Western white cedar - Libocedrus decurrens.

The yellow cedar of the Pacific is Cupressus Nutkaensis, or, as it is often called, Thujiopsis bor-ealis.