10 Wyoming Experiment Station. 



willows thev are on separate plants. The male flowers are in 

 slender, drooping clusters, while the female form shorter, 

 thicker and erect aments. The numerous fruits in the clusters, 

 when ripe, are small, flattened, one-seeded nutlets with a small 

 thin wing at either side." 



Our birches have slender, more or less spicy-aromatic, warty 

 twigs. The paper birch, which becomes quite a tree, is found 

 in the Black Hills of Wyoming. The following two are more 

 generally distributed over the state : 



Glandular Birch (Betula glandulosa Michx.) 



A small shrub, i to 6 feet high, with brown or grayish, glan- 

 dular-warty twigs and small roundish bluntly toothed leaves. 

 It is common in the wet bogs of the higher mountains. 



Western Birch (Betula fontinalis Sarg.) 



A large shrub or tree, 10 to 20 feet high, growing in 

 clumps and having smooth, dark-brown bark and grayish, 

 resin-dotted twigs. Its leaves are sharply toothed, more or 

 less pointed and from one to two inches in length. 



The western birch occurs on the banks of many of the small- 

 er streams of the state. It may be used to advantage for home 

 decoration, the clumps with their dark trunks and branches 

 and pretty foliage being very attractive on the borders of lawns. 

 Paperleaf Alder (Alnus tenuifolia Nutt.) 



A shrub or small tree, often 20 feet high and with several 

 trunks from the root. It has smooth, light-green, doubly- 

 toothed leaves, considerably larger than those of the western 

 birch. Its flowers are in clustered aments which develop during 

 summer and remain naked on the twigs over winter, opening 

 the next spring before the leaves appear. 



The paperleaf alder is common throughout the state, occur- 

 ring in large clumps on the banks of streams. This large shrub 

 may be transplanted and used effectively to adorn the home 

 grounds. 



