A FLORA IN NORTHERN OREGON 329 



Trifolium repcns L. Common in moist ground. 



Trifolium hybridum L. Frequent in moist ground. 



Trifolium spinulosum Dougl. One specimen, in damp ground 

 along the Umatilla. Our material seems sufficiently dis- 

 tinct from Trifolium fimbriatv/m to merit recognition. 



Trifolium spinulosum Dougl. Frequent along the Umatilla. 



Medicago lupulina L. Frequent in damp ground. 



Medicago saliva L. Alfalfa is practically the only crop grown 

 in the area under consideration. It is common as an es- 

 cape wherever there is sufficient moisture. 



Psoralen laneeolata scabra (Nutt.) Piper. Abundant in dry, 

 drifting sand. 



Glycyrrhiza lepidota Nutt. Common in moderately dry 

 ground. 



Hosackia americana (Nutt.) Piper. Scarce, in slightly moist 



ground. 

 Astragalus succumbens Dougl. Scarce, in dry sandy ground. 

 GeraniuHi carolineanwm L. Scarce, along the Umatilla. 



Erodium cicutarium (L.) L'Her. Very abundant throughout 



the dry area. 

 Linum leivisii Pursh. Scarce, in moderately dry ground. 



Euphorbia glyptosperma Eng. The most characteristic desert 

 annual. Hundreds of acres are reddened over by the pecu- 

 lar tinge of the foliage. 



Piscaria setigera (Hook.) Piper. Sparingly distributed in dry 

 ground. 



Rhus glabra occidentalis Torr. Found plentifully in one place 

 along the Umatilla. 



Rhus toxicodendron L. Occurs sparingly along the Umatilla. 

 Malva rotundifolia L. Common in cultivated ground. 

 Sphaeralcea munroana (Dougl.) Spach. Infrequent, on high 



dry ground. 

 Hypericum scouleri Hook. In a few places along the Umatilla. 



Mentzelia laevicaulis (Dougl.) T. & G. In a few places on dry 

 slopes. 



l/< nizelia albicaulis Dougl. Common and generally distributed 

 in the desert. 



