272 UNIVERSITY OF COLORADO STUDIES 



the beginning of summer. Pentstemon spp., Achillaea, Pseudocjrmop- 

 terus, Sedum, Chamaenerion and Castilleja spp. characterize the 

 summer season. The blossoming of any of these plants may last from 

 fifteen to twenty-eight days. The time at which each species is 

 at the height of its blooming period may be noted in the table. 



4. With the exception of the gentian and the fire weed the principal 

 plants which characterize the autumnal flora belong to the Com- 

 positae. The golden rod and species of Erigeron form yellow and blue 

 patches on the forest floor. Grasses occur abundantly at this season, 

 thirteen species being noted, as follows: Calamagrostis purpurascens 

 R. Br., Bromus porteri (Coult.) Nash., Agrostis hiemalis (Walt.) 

 B.S.P., Festuca hrachyphylla Schultes., Sitanion brevifolium J. G. 

 Smith., Trisetum montanum Vasey., Poa interior Rydb., Agropyron 

 violaceum (Hornem.) Vasey. Agropyron caninum (L.) Beauv., 

 Agropyron tenerum Vasey., Hordeum juhatum L., Panicularia holmii 

 Beal., Dactylis glomerata L. The tribes represented are Festuceae 

 (5), Hordeae (5), Agrostideae (2), and Aveneae (i). 



Besides the principal species mentioned, many secondary species 

 occur. Some species, however, were noted which do not seem to 

 belong properly in the lodgepole forest. They are probably invaders 

 from drier or moister areas. Aquilegia coerulea, Delphinium glau- 

 cescens and Geranium richardsonii were noted near the aspen groves. 

 Eriogonum suhalpinum and Capnoides aureum grew in especially 

 dry places. Anaphalis subalpina was found on the south-facing 

 slope, Leptasia austromontana formed dense mats in a few places 

 on the north-facing slope and Pyrola chlorantha occurred in shady 

 places with the twin flower {Linnaea americana). 



HERBS OF THE FOREST FLOOR 



