62 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Distribiitiitn of rhuractcristic H tKlsoiiian sitccicH — Contiinietl. 



THE ARCTIC ZONE. 



This is sharply marked hy the hi<j:h altitude timber line. As before 

 explained, this line extends to a much higher altitude, 700 meters 

 or more on Mount Rainier, on the ridges than in the draws between. 

 This, in general, is true of all the northwestern mountains. On the 

 highest mountain peaks flowering plants extend up to 3,200 meters 

 (10,500 feet) altitude. The lower portion of this zone, except 

 where there are rock outcroppings, is covered with a dense carpet of 

 grasses and flowers.' Among the more abundant of the former are 

 Festuca viridula, Poa arcfica, and Agrostis rossae. Among the more 

 conspicuous flowers in the damper places are a buttercup {Ranun- 

 culus suksdorfli) , a marsh marigold {Caltha leptosepala) , and a shoot- 

 ing star {Dodecatheon jeffreyi). On the drier slopes Puhatilla occi- 

 dentalis raises its curious tasseled heads of akenes; a lupine {Lupinus 

 suhalpinus) forms great masses of blue; a painted cup {Castilleja 

 oreopola) makes mats of dull crimson, and a cinquefoil {Potentilla 

 flahellifolia) furnishes an abundance of yellow. Even more con- 

 spicuous are the two " heathers," Phyllodoce empetriforniis and 

 Cassiope mertensiana, the former with clusters of rose-purple flowers, 

 the latter with the clusters pure white. 



Along the rills a beautiful blue gentian {Gentiana calycosa), the 

 crimson mimulus (Mimnlus lewisii), and the yellow arnicas make 

 parti-colored borders. 



Two small plants, a saxifrage {Saxifraga tolmiei) and Liitkea 

 pectinata are conspicuous only because they form dense mats. 



