IOWA ACADEMY OF SCIENCE 
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33. Taphria Johansonii Sadeb. 
On Populus tremuloides Michx. 
Common on the immature aments of the aspen, causing a thickening of the 
capsule which is a very conspicuous object owing to the bright yellow color 
of the diseased tissue. 
34. Taphria virginica Sadeb. & Seym. 
On Ostrya virginiana (Mill.) K. Koch. 
Causing a very conspicuous hypertrophy of the leaves of the host. Early 
summer. 
ORDER PERISPORIxVLES. 
Family ErysipJiaceae. 
35. Sphaerotheca Humuli (DC.) Burrill. 
On Agrimonia gryposepala Wilr, (A. hirsuta B'icknell), and Rhus glahra L. 
Not a common species, and not abundant on the hosts upon which it was 
collected. Reported by Pink on EpiloMum coloratum Muhl. 
36. Sphaerotheca Humuli eulginea (Schlecht.) Salmon. 
On Erecthites hieracifolia (L.) Raf., *'Erigeron canadensis L. (Leptilion 
canadense Britton), Taraxicum officinale Weber (T. Taraxicum Karst.), and 
Veronica virginica L. (Leptandra Nutt.) 
Not uncommon on various weeds. Also reported by Pink on Bidens frondosa 
L., and Sonchus oleraceus L. 
Sphaerotheca pannosa (Wallr.) Lev. 
Reported by Fink on Rosa dlanda Ait. 
Sphaerotheca mors-uvae (Schw.) B. & C. 
Reported by Fink on RiJjes Cynosbati L, and R. rotundifoliuni Michx. Conidia 
collected on R. floridum L’Her during the past summer may belong here. 
37. PODOSPHAERA OxYCAXTHAE (DC.) de Bary. 
On Prunus amcricana Marsh., and P. avium L. 
Not uncommon on species of plum and cherry. Reported by Pink on an 
unidentified species of Prunus. 
38. PODOSPHAERA LEUCOTRicHA (E. & E.) Salmon. 
On Pyrus Malus L. (Malus Malus Britton.) 
Collected once on seedlings, 
39. Erysiphe Pologoni DC. 
On Polygonum aviculare L., P. erectum L., and Ranunculus abortivus L. 
Abundant on various herbacious plants. Reported by Pink on Astragalus 
canadensis L. {A. caroliniana L.), and Oenothera biennis L. (Onagra Scop.) 
40. Erysiphe cichoracearum DC. 
On ^Ambrosia artemisiae folia L., *A. trifida L., Aster cordifolius L., A. 
puniceus L., A. salicifolius Ait., Cirsium discolor (Muhl.) Spreng (Carduus 
Nutt.) Eupatorium urtiaefolium Reichard {E. ageratoides L. f.), Helianthus 
