A FLORA IN NORTHERN OREGON 321 



At the time of our visit the spring vegetation of ephemeral an- 

 nuals and weak perennials had disappeared. This, however, 

 must have been very scant, or it would have left more traces. 

 I was told by residents that early spring flowers were here al- 

 most wanting. The following belong in this association: 



Festuca octoflora Lupinus ornatus 



Bromus tectorum Erodium cicutarium 



Agropyron subvillosum Linum lewisii 



Sitanion sp. Euphorbia glyptosperma 



Comandra pallida Piscaria setigera 



Rumex venosus Sphaeralcea munroana 



Polygonum majus Mentzelia laevicaulis 



Eriogonum niveum Mentzelia albicaulis 



Eriogonum baileyi Opuntia polyacantha 



Salsola kali tragus Epilobium paniculatum 



Abronia mellifera Pteryxia terebenthina 



Sisymbrium altissimum Gilia inconspicua 



Kunzia tridentata Coldenia nuttallii 



Piptocalyx circumscissus Chrysothamnus viscidiflorus 



Solanum triflorum Chrysothamnus nauseosus 



Nicotiana attenuata Erigeron hispidissimus 



Plantago purshii Balsamorhiza sagittata 



Ptiloria paniculata Achillea millefolium lanulosa 



Gaertneria acanthicarpa Artemisia tridentata 



This list is remarkable not only for its brevity, but also for 

 the scant representation or total absence of a number of great 

 genera that dominate most of the other arid sections of eastern 

 Oregon. Among these may be mentioned Erigonum, Arabis, 

 Astragalus, Cogswellia, Grilia, and Erigeron. 



The only association that remains to be considered is that of 

 the damp ground along the Umatilla river. We might at first 

 thought expect to find here the same species that occur along 

 the Columbia, but in fact we meet with not only A T ery different 

 forms, but a far greater variety. These are mostly Transition 

 species which, while having plenty of moisture, are protected by 

 their situation from the floods and winds to which those growing" 

 along the Columbia are» exposed. The margins of the Umatilla, 

 then, may be looked upon as forming a very narrow strip of 

 Transition territory extending down to the lowest level of the 

 Upper Sonoran that is to be found anywhere in the state. Many 

 of the species are poorly represented, as might be expected from 

 the smallness of the area. Even with these omitted, however, the 



31 



