82 
Septoria G:nothere often occurred in company with the mildew 
and together they did much damage. Cnothera Missteae 
growing in the garden was somewhat affected by the mildew. 
PERONOSPORA CYPARISSLZ, DeBary. 
The mildew of our spurges seems to belong to this species 
rather than to P. Euphorbia. All my specimens agree with 
DeBary’s description. The fungus grew plentifully on Euphor- 
bia glyptosperma and E. maculata. \t appears on the under 
side of the leaves, petioles and branches, and is most 
plentiful on the central branches, causing them to <7 
an upright mode of growth. It has aided very materially m 
checking the growth of these weeds. 
PERONOSPORA EFFUSA (Grev.), Rabenh. 
Very plentiful on spinach (Spinacea oleracea) and goosefoot 
(Chenopodium album and C. hybridum). It has been very de- 
structive to all hosts and especially so to spinach. All of these 
plants grown in the college gardens were so badly affected as to 
be hardly fit for any use at all, and were destroyed long ac 
the season was over. It was often associated with a “ leaf-spot 
fungus (Stegonospora Spinacee, E. & E. n. sp. in litt,) which bids 
fair to become a serious pest. 
PERONOSPORA LEPTOSPERMA, DeBary. 
Common on Artemisia biennis during June and early July. 
It was usually destructive to the affected leaves, but did little 
injury to the plant as a whole. 
PERONOSPORA PARASITICA (Pers.), DeB. 
This species has done good service in killing off many of the 
crucifers of weedy habits. It has been very plentiful. ben 
plants found in this vicinity affected by it are: Brassica eT ee 
B. alba, B. Sinapistrum, Sisymbrium canescens, Lepidium wler- 
medium, L. Virginicum, L. sativum, Capsella Bursa-pasto™™ 
Nasturtium hispidum, N. Armoracia and Raphanus sativus. «3 
damage done to the two last hosts was slight, however, 5° the 
mildew has been decidely beneficial. 
PERONOSPORA VIOL&, DeB. | 
Quite plentiful on pansies ( Viola tricolor) in flower gardens 
during the latter part of August and early part of September 
Very injurious. . 
