CONIFERS OF THE ROCKY MOUNTAIN REGION. 33 



The male and female flowers are borne on the same tree, but each 

 sort is usually on different twigs. They are minute, inconspicuous, 

 elongated bodies, especially the female flowers, borne at the ends of 

 the twigs and opening, as a rule, in early spring. 



The small solitary cones (PL XI) mature in one season, shedding 

 their minute, very narrowly winged seeds in early autumn (PL XI, a) . 

 The cones, strongly bent back upon the branchlets, are composed of 

 about 8 thin scales, which are arranged in pairs, each pair set at right 

 angles with the preceding one, just as in the arrangement of the 

 leaves. The two or three middle pairs of scales, which are larger 

 than the others, each bear two seeds. The thin, gauzy seed wings, 

 attached on two sides of the seed, and alwa} T s of a lighter color than 

 the body of the seeds, render the seeds very buoyant, so that they are 

 carried by the wind for long distances from the parent trees. Minute 

 resin cells in the seed coats give the seed a strong aromatic or cedar- 

 like odor similar to that of the wood. 



The wood of the Thujas is very light, soft, and has a characteristic 

 aromatic or cedarlike odor. It is exceedingly valuable for timber, 

 particularly on account of its durability under all kinds of exposure, 

 and especially in earth and water. 



Two species of this group are indigenous to the United States and 

 Canada. One, a small or medium-sized tree, inhabits our northeast- 

 ern States and adjacent Canadian Provinces; the other, a very large 

 tree, grows in northwestern United States and northward in the 

 Pacific coast region to Alaska. 



Trees of this genus are of ancient origin, representatives of them 

 having existed throughout the northern hemisphere during the upper 

 Cretaceous and Eocene periods of the earth's history. Remains of 

 them are foimd abundantly in the Baltic amber (Oligocene) and in 

 the Miocene of Europe and North America. Geologic remains of our 

 northeastern white cedar, Thuja Occident alis, occur in the Pleisto- 

 cene formation of Canada, Ohio, and Virginia. 45 



WESTERN RED CEDAR; "RED CEDAR." 



Thuja plicata D. Don. 



COMMON NAME AND EARLY HISTORY. 



Like the incense cedar, the western red cedar occurs chiefly in the 

 Pacific coast region, its range in the Rocky Mountain region being 

 confined to Montana and Idaho and adjacent Canadian territory 

 (Map No. 8). 



Lumbermen and other woodsmen of the Northwest call it "red 

 cedar," or simply ''cedar," while for the most part nurserymen know 



45 Fide Dr. Edward W. Barry, paleontologist, Johns Hopkins University, Baltimore, Md. 



