50 BOTANICAL SURVEY OF THE CCEUR D'ALENE MOUNTAINS. 



TAMARACK. 

 Larix occidental! $ Nutt. 



The only species of deciduous conifer in the Cceur d'Alenes. It is 

 plentiful everywhere — in the canyons, on the mountain slopes and 

 summits, and even among portions of the low-lying yellow-pine forest. 

 It is a noble tree when seen in its favorite haunts, which are the wet, 

 gloomy canyons of the interior basins, where it often vies in size with* 

 the white pine. It grows here to a height of 30 to 60 meters (100 

 to 200 feet), frequently with a diameter of 2.4 meters (8 feet). The 

 crown is composed of short, straight branches, and is about three- 

 fifths the total height of the mature tree. The individuals that are 

 found on lower levels, especially in the yellow-pine forest, have a much 

 larger crown; often five-sixths of the entire length of the tree is com- 

 posed of this, and the branches are long, slender, and slope down- 

 ward at a high angle. Its altitudinal range is between 650 and 1,000 

 meters (2,100 to 0,200 feet), reaching its greatest size between 850 and 

 1,000 meters (2,800 and 3,300 feet). In its youth it is a rapid grower. 

 During the first 30 to 10 years the spaces between the annual rings 

 will average 5 mm. (i inch) in favorable localities. As it advances in 

 age the annual increase in its diameter becomes very much less, until 

 at 180 to 200 years and upward there is often not more than 0.5 mm. 

 (-■nj inch) between the yearly layers. The sapwood is white and forms 

 but a narrow zone a few centimeters wide. The heartwood is of a yel- 

 lowish or reddish tint, and is very heavy, full of sap, and frequently 

 seamed with long, wide gum cracks. The specific gravity of the wood 

 is slightly higher than that of the yellow pine, and the logs often sink 

 when put in water. To obviate this the butt end is sawed off a few 

 meters above the cut, or holes are drilled in the logs and tightly 

 plugged. It is largely sawed into lumber, which, however, is apt to 

 wear very rougli unless care is taken in sawing. It makes excellent 

 fuel and is one of the two trees in this region which supply most of the 

 cross-ties used by the railroads. The fiber is short and the tensile 

 strength low; it is therefore, so far as I know, never sawed into square 

 timber for bridges, beams, etc. 



HEMLOCK SPRUCE. 

 Pneit<lotsuga laxifolla (l'oir.) Britton. 



The hemlock spruce is, next to the yellow pine, the most generally 

 useful of the Ca*ur d'Alene conifers. I.oth its regional and altitudinal 

 range are very much greater than those of the yellow pine. It is found 

 in all portions of the Cceur d'Alenes, from the lowest level to elevations 

 of 2,160 meters (7,1<I0 feet). It is equally at home in the humid valleys 

 or on the well-drained mountain slopes. In the lowlands it reaches a 

 height of 50 to 70 meters (100 to 230 feet), with a diameter which seldom 

 exceeds 1.3 meters (4.2 feet); on the dry hillsides it is of slow growth, 



