November i, 1906 173 



Erigeron divergens Eriophyllum grandiflorum 



Gnaphalodes californica Rigiopappus leptocladus 



Wyethia angustifolia Senecio eurycephalus 

 Harpaecarpus exiguus 



Siskiyou County 



This county touches Shasta on the south, extending north- 

 ward to the Oregon line. The southern half is mountainous, 

 while the northern part contains several fertile valleys, notably 

 Shasta valley. 



Collections were made in early June in the gorge of the 

 Sacramento river between Dunsmuir and Shasta Springs, eleva- 

 tions from 2284 to 2536 feet. 



Above Shasta Springs is a plateau lying between Mt. Shasta 

 and the Coast Range, five or six miles wide and about ten long, 

 with elevations between 3400 and 4000 feet, part of it swampy 

 meadow land and part sandy chaparral. The species as a whole 

 differ from those in the gorge of the Sacramento, 1000 feet 

 lower. Ceanothus cordulatus and C. velutinus are the chief 

 components of the chaparral growth, the former at lower, the 

 latter at higher elevations, while the swampy meadows support 

 growths common to such places. 



From Black Butte Summit, there is a gradual descent on 

 the north side of the plateau to Shasta valley at Edgewood, ele- 

 vation 2950 feet. The valley is devoid of natural arborescent 

 growths, and presents abundant evidence of former volcanic 

 activity in the vicinity. It is about forty miles long, with a 

 gradual slope northward to Thrall, elevation 2179 feet, at the 

 foot of the Siskiyou mountains. Its flora is essentially different 

 from that of the plateau about Sisson, and contains some small 

 proportion of species which normally are found in the Great 

 Basin region. But many of the species are peculiar to the val- 

 ley and have not been found outside of it. 



As might be expected, only a few species are the same as 

 those enumerated from Kern county; but of the six not one ag- 



