290 THE PLANT WORLD. 



The boulders are covered with a blackish moss, Grimmia, in 

 dense cushions, while Orthotrichiiiii laevigatuui prefers the 

 combined shade of boulder and brush. Monfia rubra is found 

 along the water line, and M. Sihcrica higher up. The Grease 

 wood, Ccrcocarpiis intricatus, called Mountain ^Mahogany, an 

 intricate much-branched low shrub, with sparse, small, green 

 leaves, is found straggling along the bank. Still further accen- 

 tuating the arid appearance of the vegetation is the cactus, 

 Opuntia polyacantha. 



Along the ledges of the gulches Andihcrtia nicana seems to 

 thrive best. Upon distillation these leaves yield a volatile oil, 

 pleasant and penetrating, with a lasting aromatic odor. This 

 Audihertia is related to the " honey sage " or " white sage," so- 

 called, of the mesas of Southern California. Along the terraces 

 with a northeastern exposure may be found a few colonies of 

 the delicate fern, Woodsia oregana, the only fern of the region. 

 In the upper gulches Lithophragma tenella, with its peculiar 

 glandular pubescence and laciniate petals, grows in company 

 with Montia siberica, the Indian lettuce. Here also are Heu- 

 chera and Tiarella, their old stems filling up their niches. In 

 the upper stretches, clambering over the coarse talus, several 

 vines of Clematis Ugusticifolia (sp. ?) were seen at the foot of 

 a 500-foot blufif. In a gulch with some appearance of seepage 

 there was one lone specimen of Rhus diversiloba, perhaps near 

 its northern limit east of the Cascades. Nearby was that beau- 

 tiful moss, Anacolia Mensiesii, not fruiting, but always abundant 

 in its preferred habitat. The floor of this gorge was patched 

 with Grimmia montana, growing in closely mottled green cush- 

 ions, turning a reddish brown as the season closes. 



Here the lichens, some twelve species, give color and distinc- 

 tion to the different buttresses, — Lccanora chlorophanc, painting 

 walls with a rich chrome-yellow, to be distinguished for two or 

 three miles when contrasted with the red of Placodium elegans, 

 shading off into another Placodium ferriiginca; then re-touched 

 in another section with the bluish-gray of Lecidea cacrulescens, 

 which in turn is brightened by Lecanora rubina. 



Other thalloid lichens, as Peltigera canina, were plentiful. 



