224 



The Plant World. 



On climbing out of the valley of the Paradise P.iver one 

 comes into stretches of open park-like forest with a floor of mead- 

 owy character. Over this regie n heavy snowfall often occurs 

 as late as the first week in July, while at the Inn at 5,820 feet 

 altitude frost occurs on every calm night throughout the summer. 

 On the morning of August Sth we observed plants of Xerophyllum 

 tenax, Pctlicu/dyis bracfeosa and R(tnn7ici4lus Suksdorfii which 

 had been thawed Ijy the early morning sun and were limp from 

 frost. Tlie cc^ld air currents that flow down -the mountain 

 slo})es during the night are followed b\- midday temperatures 

 of 7.S degrees to 80 degrees, changes which follow so rapidly 



FiE 



'I'suf/a Xlei Icnsiaua and CItamaecyparis iioolkatensis near timber line 



that plants frequently perish for lack of water. The principal 

 trees in these park-like forests are the Fir and the Hemlock. 

 They reach a height of from fort\- to eighty feet, and branch 

 from the gnuuid up with a spread of limbs of no more than ten 

 feet, Tliesc trees commonly grow in groups of four or five to 

 fifteen or twent\-, and tliis habit is also characteristic of the 

 shrubs; including Pi;?/r occidrntn/i\. PhyJIodoce empetriformis 

 (the red heather), I'achisiima myrsiniies, and Spiraea densifiora. 

 The Willow r f these altitudes, Salix ienera, and the Alder, A/nu.'^ 

 \nuiat(i, are found only in the most favorable situations. One 

 of the hardiest of the herbaceous plants is Pulsatilla occidentalis , 



