forms, which make themselves at home here witli surprising 

 facihty. 



The area covered inckides the city of Salem and that part of 

 the Willamette \'alley in Alarion and Polk Counties contiguous 

 to the cit}', extending to the foothills of the Cascades on the 

 east and those of the Coast Range on the west, and up to an 

 elevation of perhaps 1,000 feet. The Santiam River may be 

 regarded as the boundary to the south, and no collections have 

 been made more than ten miles north of Salem. No attempt 

 was made to reach the grasses of higher elevations. A number 

 of mountain species would be added by a survey of the subalpine 

 and alpine zones of the Cascades. 



The Willamette Valley in this part of its course is in general 

 a wide alluvial plain, lying not more than 200 feet above sea- 

 level, with \ery slight undulations of surface. From the foot- 

 hills on the east to those on the west the average width of the 

 valley is about 25 miles. The greater part of the area is under 

 intensive cultivation. Hops and grain were formerly the chief 

 crops, but fruit-growing is rapidly becoming the leading industry. 



Immediately south of Salem a range of hills, known on the 

 west side of the Willamette as the Eola Hills, with a maximum 

 elevation of about 1,100 feet, crosses the valley from southeast 

 to northwest. This range seems to represent a very recent geo- 

 logic upthrust, and the basaltic rocks which form its core are 

 heavily charged with iron, giving to the soil a characteristic red 

 tinge. The Willamette River seems to have originally made 

 its way through these hills along the valley now followed by the 

 Southern Pacific Railway from Jefiferson to Salem, and later to 

 have been diverted into the present channel, which has cut a 

 deep gorge through the hills north of Independence. The soil 

 along this old riverbed is made up of stratified boulders and gravel, 

 with a comparatively small admixture of sand and loam. In 

 other parts of the valley there is a subsoil of tough yellow clay 

 overlaid by a rich friable loam, in many places beginning to 

 show exhaustion after se\enty years of continuous cultiv-ation. 

 Numerous small streams tra\'erse the area. Mill Creek being 

 the most considerable. These are fringed with a heavy growth 



