216 BULLETIN UNIVERSITY OF MONTANA 



I. Leaves scale like. 



a. Leaves four ranked, the side ones ridged, the branchlets 

 thus appear flattened 3. Thuya (arbor-vitae) . 



b. Leaves four ranked and all ridged, the branchlets thus 

 appear four sided 4. Juniperus (juniper). 



IL Leaves needle like. 



a. Leaves jointed from a base that remains after the leaf is 

 shed. 



Leaves flat, petiolate 5. Tsuga (hemlock). 



Leaves sessile, and ridged on both sides 



6. Picea (spruce) . 



b. Leaves not jointed from a base that remains after the 

 leaf is shed. 



Leaves short petiolate leaving a triangular scar when 



shed 7. Pseudotsuga. 



Leaves sessile leaving a round scar when shed 



8. Abies (Fir). 



The genus Larix is easily distinguished from the other genera by the 

 fact that it is the only deciduous conifer in Montana. There are two 

 species in Montana. 



Western Larch (1) (Larix occidentalis Nutt.) : 



This tree is known in the Flathead valley as the tamarack or larch. 

 The new shoots have the leaves scattered. In the axils of these leaves 

 appear buds which develop into short branches with a cluster of leaves 

 at the end. Bach year this short branch grows slightly in length, and a 

 new ring of wood is added. The grov/th in length is so little, however, 

 that the branchlets never become long. The leaves are soft compared 

 with the other conifers, and have a lighter green color by which they may 

 be distinguished in the forest. In the fall they turn yellow green and 

 drop about the middle of October. The leaves are about one and a half 

 inches long. Compared with those of other conifers the cones are small, 

 but are about twice as large as the eastern tamarack (Larix iaricina 

 (Du Roi.), Koch.) They are from one to one and a half inches in length. 

 The bract is longer than the scale. (2) 



The bark (Fig. 7) of the older trees is smooth at first, then becomes 

 deeply ridged, and when the tree is 75 to 100 years old, it is at the base 

 four to five inches thick. It breaks up into oblong plates and is covered 

 with scales which break off in scroll shaped patterns. These scales are 



(1) In this article the common and scientific names suggested by 

 Sudwoilh of the United States Bureau of Forestry will be used. Nearly 

 all of the western conifers have closely related species in the eastern 

 part of the United States, and many have the same common names as 

 their eastern relatives. It is desirable, therefore, to distinguish them 

 by choosing a name that is not already in use. However, with these 

 there will be given other common names that are in local use. See 

 Sudworth, G. B., Check list of the forest trees of the United States, their 

 names and ranges. Bull. No. 17, U. S. Dept. of Ag., Div. of Forestry. 



(2) It may be well to state that the fruit of the conifers, known as 

 the cone, is made up of closely imbricated scales. To the upper surface 

 of each scale, two seeds are attached: on the lower surface, "bracts" are 

 found. Usuallv the bracts are shorter than the scales. 



