162 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Ascocarps scattered on the leaf, shining black, up to 1 mm. 

 long; asci clavate, 8-spored; spores nearly as long as the ascus, 

 90-120 X 1.5 M- Conidia cylindric, hyaline, 

 continuous, 6-8 x 1 /t. 



L. brachysporum Rost. 



Perithecia epiphyllous; asci cylindric, short- 

 stalked, apex rounded, 120 x 20-25 p., 8- 

 spored; paraphyses bacillar, apex curved; 

 spores oblong, l-rowed, hyaline, 28-30 x 

 9-10 /x. 



It is common on pine leaves.^ 



Several other species are parasitic upon 

 various conifers, among them: L. macrospo- 

 rium (Hart.) Rehm, on spruce leaves, in 

 Europe and America; L. nervisequum (D. C.) 

 Rehm, on fir leaves, a very destructive 

 European species; the pycnidial stage is 

 Septoria pini Fuckel; L. juniperinum (Fr.) 



s^°"^ After R^m''^' ^ ^°*' °^ juniper leaves and twigs in 

 Europe and America; L. gilvum Rost., on 

 pines; L. abietis Rost., on spruce leaves; L. laricinum Duby, on 

 larch. The last four species are European. 



Fig. 114. — L. pinastri. 

 H, habit sketch ; J, 



Dichsenaceae (p. 160) 

 This family contains the single genus Dichsena. 



Dichsena Fries 



Apothecia grouped in rounded spots; at 

 first sunken, then erumpent, rounded or elon- 

 gate, dark brown; asci irregularly pyriform, 4 

 to 8-spored; spores eUipsoidal, at first 1-celled, ^ ^^ ^^ 



at maturity multicellular; paraphyses filiform, pm ns^l^^erium 

 Some seven species are found upon various maerosporum. Af- 



trees. terHartig. 



D. quercina Fr. causes rough black patches on bark of young 

 oaks in Europe and America; D. faginea Fr., a similar, effect on 

 beech. 



