NOTES ON THE ERYSIPHACEAE 185 
were attacked by this species. Species of Aster are the common 
host-plants of Erysiphe cichoracearum. If the fungus has been cor- 
rectly determined, the present instance is of great interest as show- 
ing that occasionally a species of mildew is able to pass directly on 
to the usual host-plants of another species (see p. 14). 
In Journ. Myc. 5: 83. 1899, Kelsey has recorded “ £. com- 
munis” on Vicia Americana var. linearis (from Helena, Montana, 
U.S. A.). Specimens communicated to me by the author show 
that the fungus here recorded is Microsphaera alni var. ludens. 
Spegazzini (79) has recorded “ &. umbelliferarum” on Bowlesia 
tenera, from the Argentine, but the fungus, from specimens com- 
municated, proves to belong to £. cichoracearum. The Erysiphe 
recorded by Bubak (g) as ‘“Z. communis” on Plantago major is 
£. cichoracearum ; specimens sent by the author are in the Kew 
herbarium. The fungus recorded by Saccardo in Rev. Myc. 
IL: 41. 1881, as “4. communis” on “ Tragopogon sp.,” proves, 
according to a specimen sent, to be E. atchoracearum. The host- 
plant is not Tragopogon ; Professor Saccardo, when sending the 
specimen, wrote on it “ fol. epilobit,” but the fragments sent were 
too small to admit of certain identification. Professor Saccardo 
also sent a specimen of the fungus. recorded (Bull. Soc. Roy. 
Bot. Belg. 28: 86. 1889, as “£. Marti” on Pedicularis resupt- 
nata from Siberia, and this proves to be Sphaerotheca humult 
var. fuliginea. Tolf, in Bot. Notiser, 1891: 219, has recorded 
“LZ. Marti” on Astragalus glycyphyllus and Vicia cassubica from 
Sweden. According to specimens (now in the Kew herbarium) 
sent by the author, the fungus on the first-named host is Micro- 
Sphaera astragali, and on the second, V/. Baumleri. The record by 
Freeman (20), of the occurrence of “4. communis” on Eupatorium 
ageratoides belongs to E. galeopsidis (see p. 194). Professor Oude- 
manns writes to me that his record (Rév. Champ. des Pays-Bas. 2: 
97. 1897), of “E. communis” on Geranium molle was based on the 
Occurrence of merely an Oidium on this host, and that the record 
(/. ¢.) of the occurrence of the same species on Verbascum Thapsus 
was “borrowed from other writers.” The fungus recorded by 
Rabenhorst (59) as “ &. Marti” on Alhagi maurorum, Vicia ten- 
ufolia, and Khabdosciadium Aucheri, in Kurdistan most probably 
belongs to E. taurica. I have seen several examples of the latter 
