50 
IOWA ACADEMY OP SCIENCE 
OEDER PERONOSPORALES. 
Family AWuginaceae. 
6. Albugo Bliti (Biv.) Kuntze. iCystopus Bliti (Biv.) de Bary.] 
On Amarantlms graecizans L. and A. retroflexus L. 
7. Albugo Candida (Pers.) Roussel. 
On Brassica nigra (L.) Koch, Lepidium apetaliim Willd., and Radicula 
palustris (L.) Moench. (Roripa Bess.) 
The commonest of our white rusts. 
8. Albugo Portulacae (DC.) Kuntze. 
On Portulaca olera'cea L. 
Common throughout the growing season. 
9. Albugo Teagopogonis (DC.) S. P. Gray IGystopus cuMcus Lev.] 
On Amltrosia art emisiae folia L. 
A widespread and variable species with numerous hosts, but locally neither 
common nor abundant. 
Family Peronosporaceae. 
10. SoLEEOspoEA GEAMiNicoLA (Sacc.) Sclircetei’. [Pero7iospora graminicola 
Schrceter.] ’ 
On Setaria glauca (L.) Beauv. and 8. viridis (L.) Beauv. [Chaetochloa sps. 
Scribn.] 
Not abundant, the oospores being found sparingly in the autumn. 
11. Riiysotheca austealis (Speg.) G. W. Wilson [Peronospora australis 
Speg.] 
On Echinocystis lohata (Michx.) T. & G. (Micrampelis Greene.) 
A single infected vine was found in Dover Township late in August. 
12. RiiysotheCxI Geeanii (Peck) G. W. Wilson [Peronospora G-eranii Peck.] 
On Geranium maculatum L. 
About half a dozen infected leaves found in early summer. 
13. Rhysotheca Halstedii (Parlow) G. W. Wilson {Peronospora Halstedii 
Parlow, Plasmopara Halstedii Berk & De-Toni.] 
On Ambrosia artemisiaefolia L., A. trifida L., Bidens eomosa (A. Gray) 
Wiegand, B. frondosa L., Eupatorium pupureum L., Helianthus doronicoides 
Lam., and Lepacliys pinnata (Vent.) T. & G. (Ratbida Barnhart.) ' 
A common and variable species with a very wide range of hosts. 
14. Riiysotheca abducens (Schroeter) G. W. Wilson. \Pesonospora obdueens 
Schrceter.] 
On Impatiens biflora Walt. 
Pound sparingly once in midsummer. 
15. Riiysotheca viticola (B. & C.) G. W. Wilson. {Peronospora viticola 
de Bary, Plasmopara viticola Berk & De-Toni.] 
