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NATURALIST'S GUIDE TO THE AMERICAS 



stands needle grass (Stipa spp.), is of 

 common occurrence. 



The cottonwood grassland plants do 

 not differ essentially from those of the 

 Douglas fir or jack pine grasslands, when 

 the region is arid. In the transition 

 region, however, the common pine grass 

 gives place to marsh pine grass (Calama- 

 groslis canadensis), and the following 

 become conspicuous forms; foul meadow 

 grass (Poa triflora), short awned brome 

 grass (Bromus marginatus), and wheat 

 grass (Agropyron caninum). In the 

 same region leguminous forage plants 

 are abundant and grow to great size. 

 In the "Pea- vine Country" masses of 

 pea-vine associated with milk vetches 

 grow to a height of 5 ft. or more. 



There is abundant evidence that the 

 grasses, at least of the dry belt regions, 

 are pioneer forms; that they constitute 

 the first cover of the soil; that they pre- 

 cede trees in the succession of plant 

 associations. In the wooded regions 

 bordering upon open grasslands, areas 

 are common where the undeveloped 

 soil of a recently formed ridge is covered 

 with grasses while the surrounding 

 country is wooded. It is also significant 

 that in British Columbia the largest 

 open grassland areas are located upon 

 the most recent geological formations 

 (Miocene) . 



Dry Belt and mountain forests 



1. Yellow pine. On the slopes of the 

 benches, which rise to an altitude of 

 2000 or 3000 ft. one may see a gradual 

 transition from the semi-desert to the 

 plateau flora, passing through the west- 

 ern yellow pine zone to Douglas fir, 

 lodgepole pine and in places Engelmann 

 spruce. Red cedar (Juniperus scopulo- 

 rum) and buckbush (Ceanolhus velutinus 

 and C. sanguineus) and the shrubby 

 Pentstemon (P. scoulerii) are sometimes 

 found in great masses at approximately 

 2500 ft. altitude. J. D. 



The western yellow pine (Pinus 

 ponderosa) type is found in almost pure 

 stands on lower benches within its 

 range, but mixed with Douglas fir as 

 it approaches the upper limit at 3000 



ft. These species come much lower 

 down on northern slopes to where soil- 

 moisture is more readily available. 

 The commercial stands in this type 

 average 5000 to 10,000 ft. per acre; 

 occasionally more. As a type western 

 yellow pine in British Columbia is con- 

 fined to dry, well-drained sites where 

 the precipitation is from 10 to 15 in. 

 and in a belt between 1500 and 3000 ft. 

 in elevation. P. Z. C. 



2. Mixed forest. In the Kootenay 

 district western larch (Larix occidenta- 

 lis) is a common tree in mixture with 

 Douglas fir, the Douglas fir-western 

 larch forming a type between the west- 

 ern yellow pine on the one hand and the 

 spruce-lodgepole on the other in the 

 same relation as the Douglas fir type 

 in the Dry Belt. Apparently climatic 

 requirements are about the same as 

 described for the latter. P. Z. C. 



3. Montane forest. On the open park- 

 like slopes, at an altitude of from 3000 

 feet to 6000 ft. within the dry belt 

 area, may be seen a most gorgeous array 

 of color; yellows contributed by mil- 

 lions of Dog-tooth lilies (Erythronium 

 grandiflorum) , balsam-root, Arnica (A. 

 cordifolia), tiger lilies (Liliwn par- 

 viflorum); stonecrop (Sedum stenope- 

 talum) ; fleabane (Erigeron aureus) ; blues 

 by tall ''forget-me-nots" (Lappula flori- 

 bunda) ; larkspur (Delphinum bicolor) ; 

 Jacob's ladder (Polemonium humile}; 

 Pentstemon (P. confertus var. coerulea 

 purpureus), Brodieas (B. Douglasii), 

 reds by Indian paint-brush (Castilleja 

 spp), columbine (Aquilegia formosa)', 

 whites by tall specimens of cow-parsnip 

 (Heracleum lanatum) ; death camas (Zy- 

 gadenus venenosus)} Indian Tatuan 

 (Claytonia lanceolata) ; Spiraea (S. lu- 

 cida), with many other colored flowers 

 in profusion. The field botanist who 

 visits the semi-desert regions of British 

 Columbia in the months of May and 

 June will reap a rich harvest in the 

 great variety of species to be obtained 

 then. J. D. 



4. Subalpine forest and meadow. The 

 timber line subalpine forest here con- 

 sists of mountain meadows interspersed 



