11 



Thalictrum polygarnum, T. purpurascens, Ranunculus Cymbalaria, 

 R. abortivus, R. sceleratus, R. septentrionalis, R. macranthus, R. 

 acris, Aquilegia Canadensis, Delphinium elatum, Geranium, macu- 

 httum, G. Richardsoni, Baptisia tinctorial.' Thermopsis montana, 

 Lupinus parmfiorus, L. perennis, Trifolium longipes, T. involu- 

 cratum, T. monanthum, Psoralea floribunda, Astragalus caryo- 

 <'<D'})us 1 A. Canadensis, A. multiflorus, A. decumbens, A. junceus, 

 A. triphyllus, Oxytropis Lamberti, Lathy rus polymorphus, L. 

 venosus, Pisum sativum, Phaseolus perennis, P. helvolus, Amphi- 

 carpcea monoica, Desmanthus brachylobus, Amelanchier alnifolia, 

 Oenothera biennis, (E. sinuata, (E. albicaulis. 



The form on Clematis is referred by authors to E. tortilis, 

 (Wallr.), or as often written, E. tortilis, Link. It seems a mistake to 

 separate it from the other forms occurring on Ranunculacece, some 

 of which have equally long appendages; especially as on Clematis, 

 these are radiant and more or less interwoven with the mycelium, as 

 is usual in E. communis, while in European specimens of E. tortilis 

 on Cornus (Rabh. Fungi Europ. No. 2033, J. Kunze, Fungi Selecti 

 Exsicc. No. 577, etc.), the appendages are fasciculate and assurgent. 

 (See also Tulasne, Sel. Fung. Carp. I, pp. 213-216). 



The forms on Leguminosce, etc., are often referred to E. Martii, 

 Lev. De Bary (Morph. und Phys. der Pilze, III, p. 40) and Tulasne 

 (1. c. p. 215) agree in considering this a synonym of E. communis. 

 Winter, however, (Die Pilze, II, p. 31) retains E. Martii and refers 

 to it all forms having hyaline appendages; but he says that he cannot 

 decide whether this character is always constant and sufficient for their 

 separation. Careful examination and comparison of the herbarium 

 specimens specially mentioned by Winter, show that this character is 

 not constant, for some of those given by him under E. Martii have 

 distinctly colored appendages, while in some of those given under 

 E. communis they are very slightly, if at all, colored. In fact the 

 coloring of the appendages seems to depend to a considerable extent 

 on the age and vigor of the specimen, being light colored or hyaline in 

 the young, and often quite dark in fully matured, vigorous specimens. 

 A portion, at least, of the appendages often remains hyaline of those 

 on Leguminosce, while in the case of those on Ranunculacece, they 

 are usually all quite dark. 



E. tortilis, (Wallr.) 



Alphitomorpha tortilis, Wallr. Verhandl Nat. Freunde, I, p. 31. 

 Erysibe tortilis, l,ink, Sp. Plant. VI, part I, p. 3. 

 Erysiphe Corni, Duby Botan. Gall. II, p. 870. 

 Erysiphe tortilis, Fries Syst. Myc. Ill, p. 243. 



Hypophyllous. Mycelium arachnoid, effuse, evanescent. Peri- 

 thecia scattered, 80-100 fi ; appendages not numerous, about 8-15, 

 dark colored, flexuous, very long, 10-14 times the diameter of the 



