Uncinula 85 



Alphito)noypha depressa, var. artemisiae is certainly ErysipJie 

 cichoracearum^ as an examination of Wallroth's type shows. Other 

 authors also (107) (204) have stated that Uncinula salicis occurs 

 on Artemisia, but it is very probable that the statement is often 

 copied from Leveille. Paque (270) has lately (1885) recorded U, 

 salicis on this host, but the specimens kindly sent to me by tliis 

 author prove to be Erysiphe cichoriacearnm. 



The record by Cooke and Peck (91, p. 170) of the occurrence 

 of the present species on Acsculus is a mistake, and refers to 

 Uncinula flcxuosa. 



Uncinula luculcnta E. C. Howe is one of the forms of U. 

 salicis on poplar, and has been correctly referred to this species 

 by American botanists. 



U. heliciformis E. C. Howe (on Popuhis balsamifcra in the 

 United States) cannot be separated from U. salicis, although it is 

 in certain respects a marked form. Howe (167) described the 

 appendages as "spirally coiled above, colored at base," and on a 

 specimen (now in the Kew Herbarium) sent to Cooke, has 

 remarked, "possibly a variety which unites U. spiralis B. & C. 

 with U. ampclopsidis Peck." An examination of this specimen 

 showed the perithecia to be 80-1 20 /i in diameter with 24-38 col- 

 orless aseptate appendages, about i >^ times the diameter of the 

 perithecium. The apex of the appendages is, when mature, 2-3 

 times coiled in a helicoid manner (Fig. 85), and in this respect is 

 similar to that of U. nccator {U spiralis). In all other characters, 

 however, especially in the colorless aseptate appendages " U. 

 heliciformis'' shows no affinity whatever with this species. It is 

 certain, too, that a more or less helicoid apex to the appendages 

 must be regarded as a character of very little value, as it appears 

 occasionally in species which normally have a simply uncinate 

 apex, e. g., U. viacrospora, U.fraxini, etc. Among some speci- 

 mens of U. salicis sent to me by Professor :\Iassalongo, from 

 Italy, an example occurs on Popuhis nigra in which man>', though 

 not all, of the appendages have a distinctly helicoid apex. On 

 the whole, therefore, " U. hclici/onnis" must be ranked as only an 



interesting form of U. salicis. 



Erysiphe populi PatouiU. on Popnhis trenmla from China 

 (Yunnan) is U salicis, and was described from immature peri- 



