28 BULLETIN 680, U. S. DEPARTMENT OF AGRICULTURE. 



even on different twigs of the same branch, but as a rule they are 

 borne on different trees. 



The small cones (PL IX, a) which mature in one season, are com- 

 posed of 3 pairs of scales (practically of only 2 pairs). The first 

 or basal pair is at the base of the cone; a second pair, the largest, 

 forms most of the cone's body and incloses 1 or 2 winged seeds (PL 

 IX, c) on each of its scales; the third pair is joined into a central 

 flat, thick, woody wall, upon each face of which one of the preceding 

 seed-bearing scales clasps. The seeds (PL IX, c) are ripe in early 

 autumn and are shed soon afterwards, their large wings aiding greatly 

 in wide dissemination by the wind. After shedding their seeds some 

 of the cones remain on the trees at least until the succeeding summer. 

 • All of the species of this group, eight in number, are rather large, 

 important forest trees, which produce durable commercially valu- 

 able wood. Nearly all of them are long-lived trees. One species 

 only inhabits the United States, this being confined chiefly to our 

 Pacific region. Seven other species are natives of western South 

 America, New Zealand, New Caledonia, and China. The group is 

 further interesting from the fact that in geologic times species re- 

 lated to those now living existed in the upper Cretaceous, Oligocene, 

 and Miocene periods of Europe, as well as farther north in Spitz- 

 bergen and Greenland. A well marked species of Libocedrus has 

 been found in the Miocene Lake bed at Florissant, Colo. 41 



INCENSE CEDAR. 



Libocedrus decurrens Torrey. 



COMMON NAME AND EARLY HISTORY. 



Libocedrus decurrens is variously known throughout its range by 

 such common names as incense cedar, post cedar, bastard cedar, 

 and white cedar, none of which is very generally adopted. The 

 name incense cedar is as widely used as any, and would appear to 

 be most preferable because it refers to the incenselike odor of the 

 wood, which is a distinctive feature. The other common names 

 applied to it are undesirable because they are either meaningless 

 or conflict with previously established common names of some other 

 native trees. 



Incense cedar is only sparingly represented in the western edge 

 of the Rocky Mountain region (Map No. 7), where it was first dis- 

 covered in 1871 at a point in the Washoe Mountains above Carson 

 City, Nev. Later (1911) it was again found very near the Nevada 

 line in Alpine County, Cal. Its main range lies in the Pacific slope 

 country, where Capt. John C. Fremont found it in 1846 on the head- 

 waters of the Sacramento River. The first technical name (Libo- 



« Fide Dr. Edward W. Berry, see footnote 4. 



