PLANT SUCCESSIOlSr AND RANGE MANAGEMENT. 75 



ing fclie plants that characteristically occur on and about bed grounds, 

 on trails, and on other badly depleted areas. 



The following list gives the most typical primary and secondary 

 species of the respective covers. 



Wheat-grass cover (subclimas type) : 

 Primary species — 



Small wheat grass (Agropyron dasystachyum.) 



Blue bunch wheat grass (^Agropyron spicatum). 



Slender wheat grass {Agropyron tencrum). 

 Secondary species — 



Violet wheat grass {Agropyron violaceum). 

 Porcupine-grass-yellow-brush cover (mixed grass-and-weed type) : 

 Primary species — 



Small mountain jwrcupine grass (Stipa minor). 



Yellow brush {Chrysothamnus lanoeolotus). 

 Secondary species — 



Blue foxglove (Pentstemon procerus), 



Geum (Geum oregonense). 



June grass (Koeleria cristata). 



Large mountain brome grass {Dromus marginatiis) . 



Little blue grass {Poa sandbergii) . 



Low loco (Astragalus decumhens) . 



Nevada blue grass {Poa nevadensis). 



Porter's brome grass {Bromus portcri). 



Single-flowered helianthella (Helianthella uniflora). 



Spiked fescue {Festuca con finis). 



Spiked trisetum {Trisetum spicatum). 



Sweet sage {Artemisia discolor). 



"Western fescue {Festuca occidentalis) . 



Wild bean {Lupinus alpestris). 



Yarrow ( Achillea , lanulosa ) . 

 Foxgiove-sweet-sage-yarrow cover (second- weed stage) : 

 Primary species — 



Blue foxglove {Pentstemon procerus). 



Sweet sage {Artemisia dilscolor). 



Yarrow {Achillea lanulosa). 

 Secondary species — 



Aster {Aster frondeus). 



Butterweed {Senecio columMana) . 



Cinquefoil {Potentilla filipes). 



Evening primrose {Lavauxia flava). 



False cymopterus {Pseudocymoptcriis tidestromii) . 



False Solomon's seal {Vagne7-a stellata). 



Geranium {Geranium viscossissimum) . 



Horsemint {Agastache urticifolia) . 



Large mountain brome gi*ass {Bromus marginatus). 



Low larkspur {Delphinium menziesii) . 



Low pea vine {Lathyrus leucanthus). 



Mexican dock {Rumeoe mexicanus) . 



Mountain dandelion {Crepis acumina,ta). 



Porter's brome gi-ass {Bromus portcri). 



Onion grass {Ulclica bulbosa). 



