14 BULLETIN 360, U. S. DEPARTMENT OF AGRICULTURE. 
(fig. 12), but the stimulus to abnormal branching may continue. 
Brooms are formed on all hosts attacked by this genus of mistletoe. 
Fic. 10.—Young, first infections of Rasouwmofskya cam- 
pylopoda on western yellow pine (Pinus ponderosa). 
Those of the yellow 
pine, owing to their 
loosely branched con- 
dition (fig. 12),° are 
sometimes not as con- 
spicuous as those pro- 
duced on Douglas fir 
(figs. 6, 7, and 13), 
larch (fig. 14), hem- 
lock (fig. 9), or lodge- 
pole pine. 
In all the regions 
where the yellow-pine 
mistletoe has been ob- 
served in the States of 
Washington, Oregon, 
Idaho, Montana, and 
South Dakota, broom- 
ing is a common result 
of the growth of the 
parasite on this tree. 
Correspondents in Wy- 
oming, Utah, and Colorado report that old infected trees are seldom 
without them. MacDougal (8)+ refers to the excessive brooming of 
yellow pine by. mis- 
tletoe in the South- 
west. Meinecke (10) 
refers to the very 
conspicuous brooms 
on Jeffrey pine, 
sugar pine, yellow 
pine, lodgepole pine, 
and Douglas fir. 
The old brooms of 
the Douglas fir, be- 
cause of the long, 
trailing, willowlike 
branches of the 
lower portion of the 
broom, are more con- 
Fic. 11.—A larch branch, showing the result of a first infec- 
tion at its base by Razoumofskya laricis. ‘This is the be- 
ginning of a burl at this point, which will spread to the 
spicuous than those of other conifers (fig. 18). They sometimes 
attain an immense size, often including the entire crown (fig. 6). In 
1 Reference is made by number to “ Literature cited,” p. 39. 
