54 Muhlenbergia, Volume 9 
where many trees of the largest size are frequent along the San 
Antonio and Naciemento rivers, according to Jepson, in Silva 
of California. 
While scattered trees are found in the coast region, growing 
in company with Q. agrifolia and Q. lobata in places where the 
rainfall is comparatively heavy, and fog more or less frequent, 
it is found most abundantly on the dry hills about the interior 
valleys, where the summers are hot and dry. It is especially 
abundant on the hills of Butte county, where in places it is the 
dominant tree, but is frequently associated with Q. Weslizent, 
the interior live oak, and the digger pine, Pimus Sabiniana. 
The wood is heavy, specific gravity 0.89, but is brittle, 
warps and checks easily, and is used but little except for fuel. 
The sapwood is thick. Fence posts toa limited extent are made 
from it, and at one time it was used in the manufacture of wagon 
wheel parts. 
Acorns are produced in abundance, and reproduction from 
this source is common. Coppice growth is also produced, but 
is less common. The tree grows slowly. Apart from its value 
as a source of fuel, this tree is of considerable importance as a 
ground cover for the dry slopes on which it is most plentiful. 
TWO NEW SPECIES OF CARDUUS FROM COLORADO 
By GEORGE E. OSTERHOUT 
Carduus modestus sp. nov. 
A biennial or short lived perennial, 6 to 8dm. high, slightly 
arachnoid pubescent, branching above the middle into several 
slender branches, very leafy: the lower leaves oblanceolate, 1 to 
2dm. long, pinnatelv parted into numerous triangular divisions, 
these tipped with rather small spines; the upper smaller, lan- 
ceolate and less divided, all thin, whitish tomentose beneath, 
glabrate above, moderately decurrent on the stem, the clasping 
base expanded and prickly; heads subtended by a leafy bract, 
numerous and small, about 15mm. high, the bracts stout for the 
size of the head, somewhat woolly pubescent, the outermost short 
