1920] PALMER, LIGNEOUS FLORA OF THE STAKED PLAINS 99 



rock-talus zones. Found in Noran, Irion, Garza, Randall, Potter and 



"Woodward County, Oklahom 



trifoliat 



Not uncommon on dry rocky banks and in open situations throughout 



the canyon. 



Rhus trilobata Nutt. 



Abundant on rocky banks in the Lower Cap-rock-talus zone and less 



frequent in the zones above and below it. 

 Rhus microphylla Engelm. 



A common shrub in the open Canyon-floor zone and not uncommon in the 



Lower Cap-rock zone. 



Rhus Toxicodendron L* 



Grows as a low shrub, usually less than a metre high, in the protection of 



The scandent form 



bluffs. Most abundant in the Upper Cap-rock zone- 

 was not observed anywhere in the Staked Plains. 

 Opuntia leptocaulis DC. 



Common in the Canyon-floor zone and extending into the zone 



above. 



Atriplex canescens (Pursh) James. 



A common shrub in the Canyon floor and Lower Cap-rock zones. 



Zizyphus ohtiisifoHus Gray. 



One of the commonest shrubs in the Canyon-floor zone and extending 



into the zone above. 



Sapindus Drummondii Hook, & Am. 



The Soapberry, usually called Wild China or Wild Chinaberry in Texas, 

 is a common tree in the canyon, generally growing in the open ground of the 

 Canyon-floor zone or on the river banks. It sometimes extends to the foot 

 of the lower cap-rock. 

 Forestiera neo-mexicana Gray. 



A common shrub on rocky banks from the Lower Cap-rock to the River- 

 bank zone. 

 Forestiera puhescens Nutt. 



In similar situations to the last but less common. 

 Lycium Berlandieri Dunal. 



In the open ground of the Canyon-floor zone and extending into the zone 



above. 



Lonicera alhiflora Torr. & Gray. 



Not very common on steep banks of side canyons and along the upper 



cap-rock. 



Cephalanthus occidenialis L. 



Frequent along river banks and in depressions of Canyon-floor zone. 



Baccharis halimifolia L. 



Not very common in the River-bank zone and along margins of spring 



branches in side canyons. 

 Baccharis salicina Torr. & Gray. 

 Occasional on gypseous banks below the lower cap-rock. 



