208 BOTANICAL INFORMATION. 



pretty Platycarpum scapigerum, and then follow carpets of 

 Claytonia (386, 317, 387), of Fritillaria (315) with a 

 small drooping yellow flower, sometimes it has a fulvous 

 belt across the petals ; also dense masses of Collinsia (462), 

 and of Phlox? (371), both diminutive, but pretty plants. 

 On the southern slope of this place come, at last, Phacelia 

 (463), Ferula (301), Arabis aurea, with Saxifraga (Gli> and 

 625), both very common throughout the Oregon. 



Just the same flora appears about two weeks earlier on the 

 rocky islands of the Columbia, near Fort Colvilie ; but in no 

 other locality did I find these plants all together, nor in such 

 quantities. 



We will now survey the sunny basaltic rocks, walling these 

 fertile highlands, along the valley of Skitsoe river. 



The plant which always accompanies the basalt or trap 

 formation, from the Upper Platte through Oregon, is the 

 Mahonia aquifolia. It forms low shrubs, not so slender as in 

 Europe, but with larger and thicker leaves, and every part is 

 more robust. I have found gentle mountain slopes, down to 

 a fork of Muddy River, where the Mahonia had taken sole pos- 

 session for a mile or so, appearing as if sown there; only a 

 few specimens of Prunus were scattered through these mas- 

 ses. In Upper Oregon it is invariably seen growing on 

 sunny banks with the large species of Peucedanum (328), 

 it shows a great profusion of flowers about the middle of 

 April, in the stamens of which I observed the same irrita- 

 bility as in the common Barberry , but only at noon. The 

 berries have an agreeable acid taste, more so than those of 

 the European species, and the Indians collect them, but seem 

 not very fond of them. 



{To be continued.) 



