456 DISEASES OF CULTIVATED PLANTS 



conidiophore bears at its apex a single elliptic-oblong, 1-5- 

 septate, most frequently 3-septate, brown conidium averaging 

 36X15/^. 



Ascospora stage. Perithecia black, depresso-globose, not 

 papillate, and mouth indistinct or absent, 100-130 p. diam., 

 spores elliptic-fusoid, ends obtuse, continuous, hyaline, 5-6- 

 guttulate, 15X5-7 p. 



The early spring infection is undoubtedly due to conidia 

 produced on the shoots that were attacked the previous 

 season. All such should be removed. Spray with self-boiled 

 lime and sulphur wash. 



Prillieux, Malad. des Plantes Agric, 2, p. 337 (1S97). 

 Vuillemin, Journ. dc Bot., 1, p. 315 ; 2, p. 255 (1S88). 



PHLEOSPORA (Wallr.) 



Perithecia imperfectly developed, often formed from the 

 modified matrix. Spores elongated, 2-many-septate, hyaline. 



Septoria is distinguished from the present genus by the 

 presence of a distinct perithecium. Approaching the genus 

 Septogloeum in the rudimentary perithecium if indeed distinct. 

 In the last-named genus the perithecial wall, as such, is 

 absent. 



Minute fungi growing on leaves. 



Hawthorn leaf scorch. < aused by Phleospora oxyacanthat 



(Desm.), forming crowded, yellowish spots on hawthorn 

 {Crataegus oxyaeanthae) leaves; spreads rapidly, giving to 

 the tree or hedge the appearance of having been scorched. 

 The minute, imperfei t perithecia arc mostly present on the 

 spots on the under surface of the leaf. The hyaline, many- 

 septate spores ooze out of the perithecia in the form of a 

 visi id tendril, and measure 70-80X5 -7 /'. 



The fallen Ka\es should be collected and burned. Spray 

 with potassium sulphide to arresl the spread of the disease. 



Phleospora ulmi (Wallr.) forms small spots on living leav< s 

 nf the elm. Spores almost cylindrical, becoming 4-septate, 

 50-58x5-6 /<. 



Phleospora acerts (Sai c.) causes reddish specks or blotches 

 on living leaves of sycamore and maple. Spores narrowly 

 subclavate, 3-septate, 20-28x5 /' 



