Rydberg: Phytogeographical notes 463 



Douglasia montana and Eritrichium elongatum. Acomastylis 

 (Sieversia) turbinata is found in a depauperate form on the crests 

 and in better development in the meadows. The beautiful paint- 

 brushes, Castilleja occidentalis and C. Haydeni (southern Rockies), 

 are found mostly on the slopes, connecting the crests with the 

 meadows. 



Of the grasses, Poa rupicola, P. Pattersonii, P. Lettermanni, 

 Festuca brachypliylla, F. saximontana, F. supina, and Agropyron 

 Scribneri are mostly limited to the crest themselves, while Trise- 

 tum subspicatum, Deschampsia curtifolia, Agropyron andinum, 

 and A. latiglume frequent the slopes or even run down into the 

 meadows. 



The following plants are the most common and most generally 

 distributed alpine xerophytes belonging to this formation: 



*Calamagrostis purpurascens *Heuchera parvifolia 

 Trisetum subspicatum Potentilla quinquefolia 



Deschampsia curtifolia Acomastylis turbinata 



Poa rupicola *Dasiphora fruticosa 

 *Poa crocata Dryas octopetala 



Festuca brachypliylla *Dasystephana affinis 

 Festuca saximontana Trijolium dasyphyllum 



Agropyron Scribneri * Phlox caespitosa 

 Oreobroma pygmaea Castilleja occidentalis 



Alsinopsis obtusiloba Antennaria media 



Silene acaulis * Antennaria aprica 



Draba oligosperma *Senecio Purshianus 

 Draba andina Erigeron simplex 



Draba densiflora Erigeron compositus 



*Draba aurea Erigeron multifidus 



Smelowskia americana Erigeron trifidus 



*Sedum stenosepalum 



The following are common and important plants of this forma- 

 tion in the southern Rockies, but lacking or rare in the northern. 

 Those vvith the asterisks are mostly found near or below the timber- 

 line, those with the dagger are found in the northern Rockies but 

 are rare: 



* Those with asteriks are mostly found near the timber-line and also below. 



