530 LANDSCAPE GARDENING. 



noblest addition this genus ever received. Accustomed as we 

 are to regard the Arbor vitae as a small bush, principally avail- 

 able for hedging or single specimens, ten to twenty feet high, 

 for small villa-gardens and village-yards, we shall find it diffi- 

 cult to realize that we are to have an arbor vitas reaching to 

 the dignity of a majestic tree, one hundred and forty feet up- 

 right, with a fine umbrella-shaped top and picturesque head. 

 This is another of the giants from the Columbia river and 

 Nootka sound. Mr. Jeffrey discovered it along the banks of 

 Scott's river, and sent it home to England as Thuja Craigiana. 

 Mr. Nuttall, in his Rocky Mountain expedition, also discovered 

 it, and gave it the name of Thu. gigantea ; and finally, Dr. 

 Torrey has classed it as a Libocedrus, and distinguished it as 

 decurrens. It has since again been discovered in California, 

 in 1853, by M. Borusier de la Riviere. 



It has been discovered so many times, by different people, 

 and received different names, that a good deal of confusion 

 exists about it, and it is often confounded with another Thu. 

 qigantea so named by Sir William Hooker, in his American 

 Flora but which, though coming from California, is a more 

 slender tree, not over fifty feet, and is beyond doubt, the true 

 Thu. Menziesii, which is also sometimes called Thu. plicata, 

 and very much resembling the American arbor vitae. In fact, 

 it would seem as if there often existed among Arbor vitaBS 

 botanical rather than physical differences, which often, as in 

 this case, and that of the Siberian Arbor vitas, produces great 

 perplexity. 



As these two giganteas are completely mixed up, we will 

 describe them separately, with the hope of throwing some light 

 upon their difference. 



The real Thu. gigantea has its branches rather erect, long, 

 slender, and spreading laterally, with numerous smaller ones ; 

 branchlets, short, flattened, channeled along the sides ; leaves, 

 awl-shaped, lanceolate, loosely imbricated in four rows, the 

 outer pair being the longest, and folded partially over the inner 

 pair on both sides, giving the young shoots a trident-like ap- 

 pearance. 



The Thu. Menziesii, on the contrary, has its branches spread- 

 ing, flat, more or les? horizontal, slender, and of a deep brown 



