PESTS OF THE FLOWER GARDEN. 



379 



short deciduous pedicel at the base. The teleutospores differ from those 

 of Puce in la in being one-celled. The colour is also brown. 



The uredospores are supposed to be unknown, although the pustules 

 of the teleutospores are said to be sometimes intermixed with the cluster- 

 cups. Never having seen them in this connection, we cannot vouch for 

 the authenticity of the assertion. 



This endophyte has been recorded, not only in Britain, but also in 

 France, Germany, Austria, Italy, and Asiatic Siberia. 



Sacc. SylL vii. 2007 ; Cooke M.F. 227. 



Primrose White Mould. 



Ovular ia interstitialis (Cooke), PL VI. fig. 67. 



Under the name of Peronospora interstitialis this mould was first 

 made known by Berkeley in 1875 from specimens obtained from Scotland, 

 but at the time he seems to have had a suspicion that it was not a true 

 Peronospora, since confirmed. It was afterwards emoted as Bamularia 

 interstitialis ; but that even is scarcely tenable, and we substitute the 

 above. 



It occurs in yellowish patches on the under side of the leaves, in the 

 spaces between the veins, rarely occupying any extended surface. The 

 threads are short and flexuous, apparently unbranched ? with a few pro- 

 jecting spicules in the upper portion to support the conidia, which are 

 elliptical and either apical or lateral (which Berkeley calls "oblique"), 

 but there is no evidence of septum (15-17^ x 6-7 p). 



We believe it to be the same species as Ovularia primulana (Karst) 

 found in Finland, also on the leaves of Primula vera (Sacc. SylL iv. 

 737). 



This is the kind of parasite which is likely to be amenable to the 

 influence of fungicides, and has none of the pertinacity, or the resting 

 spores, of the rot-moulds. 



Sacc. SylL vii. 867; Berk. Ann. Nat. Hist. 1875, No. 1455 ; Gard. 

 Chron. May 1, 1886, fig. 124 ; Grevillea, iii. 183. 



Primrose White Mould. 

 Bamularia Primulce (Thum.), PL IV. fig. 68. 



The spots in this disease are circular or somewhat angular, and of a pale 

 ochraceous colour, without a definite margin, upon which the mould is 

 seated in tufts on either surface. The threads are rather long (50-60 x 5 /<), 

 without septa or divisions, but very rarely at all branched. The conidia 

 are cylindrically fusiform (20-30 x 3-6 \i) and sometimes uniseptate, or 

 with one transverse division, and uncoloured. Our own measurements 

 are somewhat different (25 x 5/x). 



Would be submissive to spraying with dilute Bordeaux mixture. 



This mould has been recorded in Italy, Austria, and Siberia, as well 

 as in Britain. 



Sacc. SylL iv. 1040 ; Sacc. F. Ital. t. 985. 



A black mould (Cercospora Primula^) seated on whitish-grey spots of 

 the leaves of Primula elatior has occurred in France. The tufted threads 



