PLANT SUCCESSION AND RANGE MANAGEMENT. 75 
ing the 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 (subclimax type) : 
Primary species — 
Small wheat grass {Agropyron dasystachyum.) 
Blue bunch wheat grass {Agropyron spimtum). 
Slender wheat grass {Agropyron tenerum). 
Secondary species — 
Violet wheat grass {Agropyron violaceum). 
Porcupine-grass-yellow-brush cover (mixed grass-and-weed type) : 
Primary species — 
Small mountain porcupine grass {Stipa minor). 
Yellow brush {Chrysothamnus lanoeolatus) . 
Secondary species — 
Blue' foxglove {Pentstemon procerus). 
Geum (Geum oregonense) . 
June grass {Koeleria cristata). 
Large mountain brome grass (Bromus marginatus) . 
Little blue grass {Poa sandbergii) . 
Low loco {Astragalus decumbens). 
Nevada blue grass {Poa nevadensis). 
Porter's brome grass {Bromus porteri). 
Single-flowered helianthella {Helianthella uniflora). 
Spiked fescue {Festuca con finis). 
Spiked trisetum {Trisetum spicatum). 
Sweet sage {Artemisia discolor). 
Western fescue {Festuca occidentals). 
Wild bean {Lupinus alpestris) .. 
Yarrow {Achillea lanulosa). 
Foxglove-sweet-sage-yarrow cover (second- weed stage) : 
Primary species — 
Blue foxglove {Pentstemon procerus). 
Sweet sage {Artemisia discolor). 
Yarrow {Achillea lanulosa). 
Secondary species — 
Aster {Aster frondeus). 
Butterweed {Senccio columbiana). 
Cinquefoil {Potentilla filipes). 
Evening primrose {Lavauxia fiava). 
False cymopterus (Pseudocymopterus tidestromii) . 
False Solomon's seal {Vagnera stellata). 
Geranium {Geranium viscossissimum) . 
Horsemint {Agastache urticifolia). 
Large mountain brome grass {Bromus marginatus). 
Low larkspur {Delphinium menziesii). 
Low pea vine {Lathyrus leucanthus) . 
Mexican dock {Rumex mexicanus). 
Mountain dandelion {Crepis acuminata). 
Porter's brome grass {Bromus porteri). 
Onion grass {Mel ica bulbosa). 
