Southeastern Washington and Adjacent Idaho. 



Si 



Rock Lake are remarkable. Upon the thin soils which seem able 

 to support only a Poa-Polygonum community and where even the 

 bunch-grass seems dwarfed, pine seedlings establish themselves, 

 rooting in the crevices, and eke out an existence for years. On 

 the rocks in early August, everything is dry and burned. Even 

 Amelanchier, cherry, and Spiraea become defoliated, still the 

 pines hold on until relieved by the advent of autumn showers. 

 Their stunted condition stands in marked contrast to their well 

 developed companions in the more protected places with deeper 

 soil. 



In the open park-like growth of the yellow pine in the moun- 

 tains it is not unusual to find fine clean-boled trees 2.53 ^ ee ^ m 

 diameter towering above one or two younger generations. In 

 other situations the forest is less open, and is then usually mixed 

 with Douglas fir. In such situations, as one would expect in a 

 transition region from prairie to forest, the ground cover is com- 

 posed more largely of prairie than of forest forms. The follow- 

 ing lists indicate the more important shrubs and herbs of open 

 pine woods : 



Amelanchier florida 

 Arctostaphylos uva-ursi 

 Ceanothus sanguineus 

 Holodiscus discolor 

 Opulaster pauciflorus 

 Pachistima myrsinites 

 Prunus emarginata 



Achillea millefolium lanulosa 

 Agropyron spicatum( including 



var. inerme) 

 Anemone piperi 

 Antennaria dimorpha 

 Antennaria luzuloides 

 Antennaria racemosa 

 Apocynum pumilum 

 Arnica cordifolia 



Rosa gymnocarpa 

 Rosa nutkana 

 Salix scouleriana 

 Spiraea corymbosa 

 Symphoricarpos racemosus 

 Vaccinlum macrophyllum 



Aster conspicuus 

 Astragalus mortoni 

 Bromus marginatus 

 Calamagrostis rubescens 

 Campanula rotundifolia 

 Deschampsia elongata 

 Deschampsia calycina 

 Drymocallis convallaria 

 Epilobium angustifolium 



