173] 



FLORA OF BOULDER, COLORADO 



25 



tinct forms of forest are discernible, the one of bull pine, the 

 other of Douglas spruce; at other times the two are mixed. 

 The Douglas spruce is at its best in moist ravines, and ascends 

 to timber-line on the mountains, while the bull pine seldom gets 

 above 9,000 feet. The following are characteristic species: 

 Botrychium Virginianum Atragene occidentalis 



Pteridium aquilinum 



pubescens 

 Pinus scopulorum 

 P. Murrayana (rare) 

 Apinus flexilis (rare) 

 Picea Parryana 

 Pseudotsuga mucronata 

 Oryzopsis micrantha 

 Muhlenbergia gracilis 

 Melica bella 

 Carex Deweyana 

 Toxicoscordion falcatum 

 Vagnera racemosa 

 V. amplexicaulis 

 Piperia Unalaschensis 

 Peramium ophioides 

 Populus tremuloides 

 Betula papyri f era 



Andrewsii 

 Chenopodium Fremontii 

 Blitum capitatum 

 Actaea arguta 

 A. arguta eburnea 

 Aquilegia coerulea (rare) 

 Anemone globosa 



Ranunculus abortivus 

 R. micrantha 



Cyrtorrhyncha ranunculina 

 Odostemon repens 

 Erysimum Cockerellianum 

 Bosseckia parviflora 

 Oreobatus deliciosus 

 Batidaea laetissima 

 Potentilla Hippiana 

 Amelanchier oreophila 

 Sorbus scopulina (rare) 

 Thermopsis divaricarpa 

 T. pinetorum 

 Tium alpinum 

 Homalobus tenella 

 H. decumbens 

 Lathyrus leucanthus 

 Xanthoxalis stricta 

 Ceanothus velutinus 

 Viola vallicola 

 V. Canadensis Rydbergii 

 Lepargyraea Canadensis 

 Chamaenerion angustifolium 

 Harbouria trachypleura 



