Witson : NortH AMERICAN PERONOSPORALES 411 
coloration light and usually not pronounced; conidiophores 
fasciculate, 200-400 x 7-9 #4, 3-5 times branched, ultimate branch- 
lets 4—8 » long ; conidia elliptic to globose-elliptic, 14-22 x 10-14 
#4; oospores unknown. 
This is one of the rarest species of the genus. It is distin- 
guishable from the preceding species by its more conspicuous 
habit of growth, the smaller conidiophores, and the less pronounced 
discoloration of the host. 
On GROSSULARIACEAE : 
Ribes albinervum Michx., Wisconsin, Davis (Fungi Columb. 
7753, on “ Ribes rubrum subglandulosum Maxim.’’). 
Ribes divaricatum Dougl., Washington, Piper 2957. 
Ribes hirtellum Michx., Wisconsin, Davis (on “ Ribes oxy- 
canthoides L.’’). 
Ribes prostratum 1’ Her., Wisconsin, Davis. 
Ribes rotundifolium Michx., West Virginia, Sheldon. 
Tyre Locatity, Liegnitz, Germany, on Rides rubrum L. 
DistRisuTION : West Virginia to Washington. Also in Europe. 
12. Rhysotheca Gonolobi (Lagerh.) 
Peronospora Gonolobi Lagerh. Jour. Myc. '7: 49. 1891. 
Plasmopara Gonolobi Swingle, Jour. Myc. '7: 119. 1892. 
Plasmopara Vincetoxici Ellis & Everh. Jour. Myc. 8: 70. 1902. 
Hypophyllous, infected area about 2-5 mm. bounded by the 
veins, rather well covered with conidiophores, epiphyllous dis- 
coloration light-brown ; conidiophores fasciculate, 300-600 x 8- 
10 2, 4-6 times branched, ultimate branchlets 6-10 # long ; conidia 
globose-elliptic,: rarely elliptic, 16-25 x 13-24#, OF even larger; 
“oospores globose, brown, about 20 # diam.” 
The type material of Peronospora Gonolobi was collected by 
Dr. J. H. Mellichamp and sent to Dr. Farlow, who distributed the 
collection for Pucinia Gonolobi Rav., the predominating parasite on 
the material, and so far as some of the specimens are concerned 
the only one. Among these latter is the one in the Ellis herbarium. 
It was, however, possible to determine positively the species of 
the host which was cited by Lagerheim as Gonolobus sp. but 
_ which isin reality Vincetoxicum hirsutum. The host of Plasmopara 
_ Vincetoxici is also the same species. This discovery ded to the 
conclusion that the two species were the same, a conclusion which 
