106 CONIFERS. Populus. 



325. Populus Fremontii, Watson. 

 Cottonwood. 



California, valley of the upper Sacramento River, south to San Ber- 

 nardino County, extending eastward in Nevada and Utah. A form dis- 

 tinguished by its sharply acuminate leaves, truncate at the base (var. 

 Wislizeni, Watson), is common along all the larger streams from southern 

 California, through Arizona and New Mexico, to western Texas and 

 southern Colorado. 



A large tree, 24 to 30 metres in height, with a trunk 1.20 to 1.80 

 metres in diameter ; borders of streams ; the common cottonwood of the 

 valleys of central California. 



Wood light, soft, not strong, close-grained, compact, liable to warp in 

 drying, difficult to season ; n;edullary rays thin, very obscure ; color 

 light brown, the sap-wood nearly white. 



CONIFERS. 



326. Libocedrus decurrens, Torr. 



Wliite Cedar. Bastard Cedar. Post Cedar. Incense Cedar. 



Oregon, south along the western slopes of the Cascade and Sierra 

 Nevada Mountains between 3,000 and 8,500 feet elevation, and through 

 the California Coast Ranges to the San Bernardino and Cuyamaca 

 Mountains. 



A large tree, 30 to 45 metres in height, with a trunk 1.20 to 2.10 

 metres in diameter ; slopes and valleys ; common. 



Wood light, soft, not strong, brittle, close-grained, compact, very 

 durable in contact with the soil ; bands of small summer cells thin, 

 dark-colored, conspicuous ; medullary rays numerous, obscure ; the thin 

 sap-wood nearly white ; largely used for fencing and in the construction 

 of water-flumes, and for interior finish, furniture, laths, shingles, etc.; 

 often injured by a species of dry rot (Dadalia vorax), rendering it unfit 

 for lumber. 



327. Thuya occidentalis, L. 

 White Cedar. Arbor-vita. 



New Brunswick, valley of the Saint Lawrence River to the southern 

 shores of James Bay and southeast to Lake Winnipeg, south through the 

 Northern States to central New York, northern Pennsylvania, central 

 Michigan, northern Illinois, central Minnesota, and along the Alleghany 

 Mountains to the high peaks of North Carolina. 



A tree 12 to 18 metres in height, with a trunk sometimes 1.20 to 1.50 

 metres in diameter; cold, wet swamps, and rocky banks of streams; very 

 common at the North, often covering great areas of swamp. 



