UnciNula 95 



As to how far the present plant has been confused with U. 

 aceris, it Is almost impossible to say. Fries (130, p. 244) (1829) 

 remarked under Erysiphe bicomis, '* Species in Accre platanoidc 

 fruticosa obvia eminus a reliquis dignoscltur maculis suis crustosis, 

 • candidissimis, contiguis^ determinatis, sericeis, semper epiphj'llis. 

 Thallus tarn inslgnis in nulla alia observatur." This evidently ap- 

 plies to the van TidasneL Levellle, also (214), in"iS5i included 

 the present plant under his Uncinnla bicornis^ as his description 

 and remarks on p. 154 show : there is also a specimen of the van 

 ^Tulasnci in Berkeley's herbarium at Kew, named in Leveillc's 



■handwriting U, bicornis (see also Tulasne (370, p- 197)- 



Acer platanoides is the usual host-plant for the present species, 

 and on this tree it appears to be not uncommon on the Continent. 

 It sonietimes however occurs on A, vionspessuIanu))i {A. irilobatiini), 

 and Jaczewski (176) and Le Breton and Niel (210) have recorded 

 it on ^, psendo'Platanus, 



Eriksson (119, p. 7) records the present variety as often oc- 

 curring with U. aceris on the same plant o( Acer platauoides, and 

 states that it causes great damage to this tree in the neighborhood 

 of Stockholm, not only to young plants in nurseries, but also to 

 large trees. 



4 



3. U. PRUNASTRi (DC.) Sacc. [Figs. 79, 80] 

 Erysiphe pninastri DC. Fl. Fr. 6; 108. 18 15; Tul. Sel. 



Fung. Carp, i: 199. 1861 ; de 



I : § xiii., 50. 1870. 



Alpliitomorpha adunca, var. / 



Freund, Verb, i: -^y. 1819. 



Morph. Pliys. Pilz. 



Ges. Nat. 



A. pninastri Wallr. Ann. Wett. Ges. 4 : 237. 1 8 1 9. 



■d^ 



PI. 6; 112. 



1824. 



/ 



Duby, Bot. Gall. 2 : 870. 1830. 



AlpJdtomorpha adunca, var. rosaccaiitm Wallr. Fl. Crypt. Germ. 



2: 755 (partim). 1833. 



Erysiphe adiinca Fr. Kickx. Fl. Cr>-pt. Erw. Louv., 139: 



(partim). 1S35. 



Erysibc adnnca, var. rosaccarum Rabenb. Kr\'pt. Fl. Deutschl. 



l: 236 (syn. excl. partim). 1844. 



