Rydberg: Phytogeographical notes 641 



To these are added in the Northern Rockies: 

 Calamagrostis Suksdorfii Deschampsia elongata 



7. Coppices and River Banks 



The following prefer more or less shaded situations among 

 bushes, or on river banks among willows, birches, or alders: 



%Savastana odorata Sporoholus cryptandrtis 



Stipa Richardsonii Panicularia nervata 

 Oryzopsis exigua " pauciflora 



" micrantha Festuca elatior 



Calamagrostis canadensis Elymus glaucus 

 " Langsdorfii 



Limited to one region : 

 Southern Rockies Northern Rockies 



Trisetum montanum Deschampsia elongata 



Panicularia Holmii Panicularia elata 



Melica Porteri Melica subulata 



8. Sand-draws ant) Sand-hills 



A few species characteristic of the sand-hill regions of Nebraska 

 and Kansas enter the river valleys, growing on sandy river-banks, 

 draws, and in bottoms of canyons. They are: 



Panicum harhipulvinatum Sporoholus asperifolhis 



Eriocoma cuspidata " confusus 



Muhlenhergia pungens " cryptandrus 

 Festuca octoflora 



To these are added in the Southern Rockies: 



Bouteloua prostrata Munroa sguarrosa 



Muhlenhergia Thurheri Elymus amhiguus 



" gracillima 



9. Hot Spring Formation 



In the Northern Rockies, especially in the Yellowstone Na- 

 tional Park, there are found many hot springs. The minerals 

 held in solution in the hot water, mostly silicates, are deposited, 



