76 
low; capsules striate, the ridges of 4 rows of cells, yellow and 
much thickened; teeth united in pairs, reflexed when dry, finely | 
granulose, appearing striolate, smoother and trabeculate at apex, 
cilia 8,as long as the teeth and smooth; spores brown, warty. 
.024—.037 mm. 
The leaves are very variable inthe same plants. The younger 
ones at the tips of the stems are very long acuminate, the older 
ones are much broader, sometimes only acute. 
We have the same species collected by J. B. Leiberg on 7suga 
Pattoniana, Traille River Valley, Idaho, received January, 189, 
No. 234. Also on Alnus rubra, Nooksack River, Whatcom county, 
Washington, W. N. Suksdorf, July 11, 1890, No. 71. 
Club-Root in Common Weeds. 
In some instances it has heretofore been somewhat difficult : 
to fully account for the almost perennial presence of Club-root 
(Plasmodiophora Brassice Wor.) in various cruciferous crop> 
Some fields of cabbage and turnip, in particular near New Bruns — 
wick, seemed to suggest that some of the cruciferous weeds might — 
harbor the enemy, and with this suspicion in mind, strengthened by: : 
the knowledge of the wide range of hosts for the Plasmodiophora : 
in the mustard family, Mr. J. A. Kelsey was asked to dig for the — 
slime mould until, if possible, it was found. The lurking pest Wa 
not far to seek, and in a short time a hundred roots of the Shep- 
herd’s purse (Bursa Pastoris), and an equal number of the Hedge? 
mustard (Sisymbrium vulgare) were obtained in the vicinity of the - 
infested cabbage and turnip fields. : 
Figure 1 shows a group of the Bursa roots affected with the 
Plasmodiophora. The roots of this weed are neither large 1° — 
fleshy like those of the turnip, and the galls are correspondingly _ 
small. Quite frequently the swollen portion is close below. hee 
crown, but in some cases the enlargement is midway of the root, — 
and frequently there are smaller galls near the tips of the roots: 
In Stsymérium (figure 2) the galls are quite different in outline, a 
being more nearly hemispherical and seemingly situated without — 
any order. There may be three or more of the galls of equal 512° 
upon a single root. They are of a darker brown color than in the 
Bursa. 
