A FLORA IN NORTHERN OREGON 333 



Chrysothamnus nauseosus (Pall.) Britt. Common in the desert 

 section, but much less so than the preceding, and often 

 wholly wanting. 



Solidago serotina Ait. Common along the Umatilla. 



Euthamia occidentalis Nutt. Abundant in damp ground. 



Tmvnsendia florifer (Hook.) Gray. Scarce, in dry ground. 



Erigeron hispidissirmus (Hook.) Piper. Frequent in dry ground. 

 Rays always white. 



Erigeron poliospermus Gray. Though Umatilla is the type lo- 

 cality of this species, it seems to be very scarce, only one 

 specimen being found. Very dry ground. 



Erigeron canadensis L. Very common in moist or moderately 

 dry soil. 



Machaeranthera attenuata Howell. Scarce, in dry ground. 



Lagophylla ramosissima Nutt. Frequent in moist to moderately 

 dry ground. 



Bidens rulgata Greene. Common along streams and ditches. 



Bidens cernua L. Common, with the last. 



Coreopsis athinsoniana Dougl. Very common along the Co- 

 lumbia. 



Balsamorliiza sagittata (Pursh.) Nutt. Frequent in very dry, 

 sterile ground. 



Heliantkus annuus L. Frequent in moist ground. 



Chaenactis doitglasii (Hook.) H. & A. Infrequent, in dry soil. 



Gaillardia aristata Pursh. Very common along the Columbia. 



Helenium autunvnale grandiflorum (Nutt.) Gray. Common 

 along the Columbia. 



Achillea millefolium lanulosa (Nutt.) Piper. Abundant 

 throughout the arid section. 



Artemisia dracunculoides Pursh. Abundant along the Colum- 

 bia and in other moist places. 



Artemisia canadensis Michx. Frequent along the Columbia. 



Artdnis-ia ludoviciana Nutt. Rather common along the Colum- 

 bia. A form witli mostlv entire leaves. 



