1887. | BOTANICAL GAZETTE. 251 
discovered this vein, he would have set Eriogonum umbellatum down 
asa good sign. But it is no sign at all, for it is profuse almost every- 
where in the mountains, where there is quartz or other ore, or where 
there is none. This species appears to confine itself to the mountains, 
and is common in the Belts and Birdtails, and the ranges about Helena. 
E. flavum is also common, and certainly is a pretty plant. We find it 
_ Mainly on the plains and in the foot-hills. While E. umbellatum seems 
equally partial to rocky and loamy soil, E. favum is found in rocky or 
gravelly ground almost exclusively. Like so many of our western plants 
it has wonderfully long, tough roots, considering its size, which penetrate 
the soil to a considerable depth, nothing daunted by the stones or other 
impediments in their downward course. The roots of this plant are cov- 
ered by a loose, papery bark, brown or blackish in color, beneath which 
the surface is reddish. I have found them nearly two feet in length, and 
about an inch thick just below the crown of dead leaves which charac- 
terize this and E. ovalifolium alike. I have never found the latter grow- 
ing so abundantly in the mountains as E. umbellatum, but it is extremely 
plentiful on the plains, growing with E. flavum. Generally speaking, it 
18asmaller plant than the two preceding, although the peduncle often 
exceeds that of E. flavum. It may be readily distinguished from the 
latter by its white appearance, smaller and denser umbels, and small 
roundish leaves. Often it is remarkably cespitose, forming small hillocks 
through the accumulation of dead leaves and the earthy substances lodg- 
img amongst them. It has been said that reliable Montana prospectors 
_ Tegarded this plant as a good indicator of silver in the soil. It may be. 
per cent. in iron. In some instances he found small per cents or 
mere traces of silver, but in the majority of cases he found none. 
This portion of Montana has been prospected over for years, plains 
4s well as mountains, and if silver were as plentiful as the abundance of 
Eriogonum ovalifolium seem to indicate, it would have been brought to 
epee ago. So far as prospecting is concerned, it is largely a game 
n 
their scientific knowledge of formation combined, have concluded no 
Precious metals were there; while shortly afterward a weather- beaten 
‘Prospector, with pack horse, pick, shovel and gold pan, would traverse 
