i8 7 ] 



FLORA OF BOULDER, COLORADO 



39 



vegetation clings. Often the streams flow concealed under the 

 dwarf spruces and firs, their existence there being known 

 only by their roaring underneath. Parry's primrose, saxi- 

 frages, globeflowers, white cowslips, gentians, red elephants, 

 several sedges, grasses, and rushes are examples of the wet 

 tundra vegetation. The Krummholtz of spruce and fir at the 

 timberline consists chiefly of Engelmann spruce, Picea Engel- 

 manni, and balsam fir, Abies lasiocarpa. The wet tundra con- 

 tinues down to the lower edge of the alpine zone, whence it de- 

 scends and coalesces with the subalpine stream vegetation. 

 The following are characteristic species : 



Lycopodium annotinum Trollius albiflorus 



Picea Engelmanni 



Abies lasiocarpa 



Alopecurus occidentalis 



Trisetum ma jus 



Poa reflexa 



P. leptocoma 



P. alpicola 



P. alpina 



Carex festiva 



C. ebenea 



C. bella 



Juncus Drummondii 



Juncoides spicatum 



Salix glaucops 



S. chlorophylla 



Bistorta bistortioides 



B. vivipara 



Alsine Baicalensis 



Caltha leptosepala 



Ranunculus pedatifidus 

 R. alpeophilus 

 Thlaspi Coloradense 

 Draba Fladnizensis 

 Clementsia rhodantha 

 Pectianthia pentandra 

 Saxifraga debilis 

 Micranthes arguta 

 Viola Canadensis Neo- 



Mexicani 

 Angelica Grayi 

 Pseudocymopterus 



tenuifolius 

 Kalmia microphylla 

 Primula Parryi 

 Androsace subumbellata 

 A. diffusa 



Anthopogon elegans 

 A. barbellatus 



