38 



authors of the Flora meant to draw their boundary-Hne I was 

 unable to determine; perhaps, like myself, they were misled by 

 the map, on which the Calapooia Range appears as a single 

 well-defined ridge. As a matter of fact, it is a complex of moun- 

 tains and valleys at least ten miles in breadth, flanked by foot- 

 hills on both sides, but with a somewhat more abrupt approach 

 on the north than on the south. To draw a botanical boundary- 

 line under such circumstances would be most difficult, for any 

 plant that succeeded in finding its way into the range would have 

 little trouble in advancing into the more open country to the 

 north. There are no summits above snow-line to be crossed, no 

 streams of any considerable width, no barren areas, no zones of 

 continuous cultivation, no appreciable change of climate — in 

 fact, the casual collector would never dream, from any outward 

 indications, that he was approaching anything as momentous as a 

 botanical boundary. It is not surprising therefore that several 

 species were collected during this trip which find no mention in 

 the pages of the Flora of the Northwest Coast. 



After this hasty survey of the southern boundary, it seemed in 

 order to visit the eastern one, and try to determine to what extent 

 the Cascades have barred the way to the flora of Eastern Oregon. 

 Here is a real mountain barrier, often rising far above snowline, 

 pierced by few avenues of travel, and with very diverse climatic 

 conditions on the two faces. The point of attack was Mount 

 Jefferson, on the eastern line of Linn County — a precipitous 

 volcanic peak, 10,500 feet in height, and so steep that only a 

 veteran Alpinist can hope to reach the summit. Much of the 

 west slope is too sheer for trees to get more than a precarious 

 foothold, and a large part of the region has in addition been 

 swept by forest-fires, so that an aridity prevails in many places 

 which would not ordinarily be expected on the western side of 

 the Cascades. It was not surprising, in an environment so 

 similar to the semi-arid region of central Oregon, to encounter 

 species which have been thought to belong only to the eastern 

 division of the state. 



Our western boundary, consisting of the Pacific Ocean, could 

 not be expected to afi'ord an avenue for any introductions except 



