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IOWA ACADEMY OF SCIENCE Vor,. XXVII, 1920 
PhyUachora pteridis (Reb.) Fckl. Common on fronds of Pteridium 
aquilinum pubescens. 
PhyUachora wittrockii (Eriks.) Sacc. On the tips of the stems of 
Linnaea longiflora. 
Plowrightia ribesia (Pers.) Fr. On stems of Ribes hudsonianum, R, 
vulgare. 
Microthyriaceae 
Asterina cupressina Cke. On Chamaecyparis nootkatensis. 
Coryneliaceae 
Tripospora elegans Cda. On stems of Sambucus pubens. 
Hysteriaceae 
Lophodermiuni arundinaceum (Schr.) Chev, On old leaves of Blymus 
mollis. 
Lophodermium pinastri (Schrad.) Chev. On needles of Picea sitchensis. 
Phacidiaceae 
Rhyiisma andromedae (Pers.) Fr. On leaves of Andromeda polifolia, 
Rhytisma salicinum (Pers.) Fr. On leaves of Salix spp. (native). 
Rhytisma vaccinii Schr. On leaves of V accinium parvifolium. 
Rhytisma sp. On leaves of Mensiesia ferruginea. 
Dermatiaceae 
Cenangium cerasi Fr. On stems of Prunus cerasus. 
Dermatea cerasi (Pers.) Fr. On stems of Prunus cerasus. 
Tympanis sp. On stems of Ribes bracteosum. This is a highly des- 
tructive parasite and causes more damage to the host than any other dis- 
ease or all other diseases to which it is subject. 
Mollisiaceae 
Fabraea ranunculi (Fr.) Karst. On leaves of Ranunculus occidentale. 
Pseudopesiza ribis Kleb. On leaves of Ribes bracteosum, R. nigrum. 
Pseudopeziza trifolii (Bernh.) Fckl. On leaves of Trifolium pratense. 
Exoascaceae 
Bxoascus cerasi Fckl. Causing witches brooms on Prunus avium. Not 
observed on P. cerasus. 
Bxoascus deformans (Berk.) Fckl. On leaves and stems of Amygdalus 
persica. 
Ustilaginaceae 
Ustilago avenae (Pers.) Jens. In spikelets of Avena sativa. 
Thelephoraceae 
Bxobasidium vaccinii (Fckl.) Wor. Causing distortions on Cassiope 
meriensiana, Menziesia ferruginea, Vaccinium vitis-idaea. 
Phomataceae 
Ascochyta colorata Peck. On leaves of Fragaria sp. 
Ascochyta pisi Lib. See Mycosphaerella pinoides. 
Ascochyta sambuci Sacc. On leaves of Sambucus nigra aurea. 
