161 



599. Sphaerotheca pannosa (Fries) Lev., Syll. I ', Syn: Erysiphe 

 pan. Wallr., Fries S. M. Ill '^^ Eurotium rosarum Fries S. M. Ill ^^\ 

 Oidium leucoconium Desm., Syll. VlII ^'^, Rosens Meldug (R 84 i), 

 Lit: R 80 a '^\ 02 a '^\ 04 a ''\ Er. 85 '^ Lind 10 k ^'°. 



This is a fungus which is fond of dry weather, accordingly it is 

 naost destructive in hot and dry summers (R 02 o), and it is never 

 found in hothouses. Besides on Rosa alba, arvensis, canina etc. it has 

 been found on Prunus persica on fruits and young twigs, Rostrup 

 considers it a special biological form (R 87 g, 92 j =^ 93 o '\ 96 o "i^^); 

 its ascigerous fructification has not yet been found on the last-men- 

 tioned host-plant. 



Podosphaera. 



600. Podosphaera leucotricha (Ell. &. Ev.) Salmon, Syn : Sphae- 

 rotheca mali Burrill, Oidium farinosum Cooke, Syll. X ^^°, Ldau VIII °', 

 ^bletraeets Meldug (R 02 a "3°, Lind 6. Ravn 10"), Lit: R 92 t, 02 3"°, 

 Magnus 98, Lustner 01 6. 10, Lind 11 b. 



The mycelium hibernates in the buds, the conidial fructification will 

 occur all through summer on many different sorts of Pirus malus, the 

 ascigerous stage is rather rare and is only found late in autumn. I 

 have also a few times found Oidium farinosum on young trees of 

 Pirus communis. It was Hrst found in this country near Tangegaard 

 on May 28. 90; as late as in 1902 (R 02 a) it was rare in Denmark, 

 since then it has spread very much. 



601. Podosphaera clandestina (Fries) Lev., R 80 a^^^ Syn: Ery- 

 siphe eland. Fries S. M. Ill ^^^, Podosphaera oxyacanthae (de Cand.) 

 de By., Syll. I ^, Podos. myrtillina Kze, Syll. I ^, Erysiphe myrt. Fries 

 S. M. Ill ^"^ Oidium crataegi Grog. Ldau VIII *^ Hvidtjernens Mel- 

 dug (R 02 a^^"), Blaabaer Meldug (R 04 a ^"). 



Crataegus monogyna common. Sorbus aucuparia, B. (Neger 06). Cydonia 

 Japonica. S. (R 92 j 59). Vaccinium myrtillus. B. Paradisbakkerne (R 06 dd "'). 

 Vaccinium uliginosum. J. Vindum Skov!; S. Gammelmose (R 06 cc ^"). 



602. Podosphaera tridactyla (Wallr.) de By., Syll. I ^ Kraege- 

 Meldug (R 04 a ■>"), Blommetraeets Meldug (R 02 a ^'^ Lind & Ravn 

 10 " c. icon.). Lit: R 80 a '^\ 93 o ^°. 



Prunus domestica, insititia, padus. 



Erysiphe. 



603. Erysiphe graminis Fries S. M. II '", Syll. I ^^ Oidium moni- 

 hoides Link, Syll. IV*, Ldau VIIP^ Oid. tritici Lib., Syll. IV ^^ Oid. 

 rubellum Sacc, Syll. IV''^ Oid. bulbigenum Sacc, Syll. IV ''^ Grsesser- 

 nes Meldug (R 02 a «= c. icon., 04 a ^='). 



J. Lind: Danish fungi. II 



