2 A Study of the Vegetation of 
Adseté, -Alnus-Sialiaeassocies tyace ote is esters slereere ions 90 
Subsere. Natural reforestation in cut-over areas and in burns ....... gI 
Hydrosere °.. ) ids axes tert ah aio oe nate eaten pie bien tien alent einen Lime 100 
Chara-Potamogeton ASSOCIES ...........ccceeesecccccees 101 
Nymphaea-Potamogeton aSSOCieS ........6eeeseeeeecncee LOZ 
Scirpus= Ly pha assOCese of Ven sabes iter tee oie 9c hat gir 103 
Eleocharis-Carex. ‘asSsocieSuneee ate een een eee 104 
Wet-meadow. associes! =v... nee nanan ese ee ree 105 
Elood=plain forest associes <-- aaah eerie nee ee 107 
Ruderal -vewetation: 0/000. oo BOs apie ale estos oe meee ee ae 109 
Conclhtisiont ss ee eee Sale oe Toe eee ee ene ieee III 
INTRODUCTION 
No one at all botanically inclined can travel through south- 
eastern Washington without being impressed with the marked 
changes which a distance of only a few miles may show in the 
vegetation. Traveling eastward from a point fifty miles west of 
the Idaho state line, one passes from a region of scab-land sage- 
brush through one of rolling hills covered with bunch-grasses. 
Upon steadily ascending the great Columbia Plateau, the bunch- 
grasses give way to well developed prairies, and these in turn, 
near the Idaho line, to forests of yellow pine, Douglas fir, white 
fir, tamarack, and cedar. Or starting from Spokane in the central 
part of eastern Washington and traveling southward, one soon 
leaves the pine woodland of the Spokane gravels and passes again 
through the rolling prairies. Projecting above the surrounding 
sea of prairie-covered basalt are islands of quartzite, the tops of 
lofty mountains almost buried under the basalt. These may be 
covered with grass land on the windward side, while at a distance 
of a few meters over the crest the prairie may give way to rather 
dense forests. Cut through the layers of basalt, in a mighty 
canyon, 1,600 feet deep, the Snake River winds its way through 
the prairie belt. Upon descending into the canyon one finds the 
bunch-grasses and sagebrush vegetation growing in a climate 
markedly different from that of the plateau above. Far south- 
ward from the canyon of the Snake River rise the pine-covered 
foothills of the Blue Mountains. 
Such is a brief glance at the wonderful field for investigation 
S 
