LEPTOSPHAERIA. 221 



just over the root, thus resembling the symptoms accompanying 

 an attack of Hessian Ely. 



L. tritici Pass, is said by Frank to be destructive to wheat in Germany. 

 (See also Cladosporium). 



L. subtecta Wint.' In Tyrol the perithecia of this species accompany 

 disease of the leave.? of Erica carnea. Simultaneously Hypoderma ericae 

 Tub. and Spha,eria ericina Tub. were found, the former appearing to cause 

 the disease (see p. 234). 



L. anceps Sacc. On living branches of Ribes nigrum. 



L. vitigena (Schulzer). On living tendrils of the vine. 



L. circinans Sacc. (see Rhizoetonia p. 201). 



L stictoides Sacc. on Liriodendron tulipifera is an American species. 



Pleospora. 



The black perithecia are not developed on a stroma, and 

 are at first concealed in the host-tissues only. They contain 

 paraphyses and eight-spored asci. The spores are multiseptate, 

 and generally coloured. 



Pleospora hyacinthi Sor.' produces black coatings on the 

 bulb-scales of hyacinth. The mycelium inside the tissues is 

 colourless, but outside is dark red, and its presence causes disease 

 of healthy parts. Certain perithecia which appear on the bulb- 

 scales in autumn may perhaps belong to this fungus. 



P. tropaeoli Hals, is given as a disease of Tropaeolum in U.S. 

 America.^ 



P. hesperideanim Catt. The conidial form {Sporidesmium 

 hesp.) appears as a black coating on the orange. 



P. ulmi Fr. {var. minor) Allescher, causes a leaf-spot on young 

 elm-seedlings, and the leaves drop off prematurely. 



P. napi Fuck, is the cause of rape-smut. Leaf-spots carrying 

 conidial cushions (Sporidesmium exitiosum Kiihn) appear on the 

 rape and other allied root-crops. 



Other " black smut-diseases " have been ascribed to Polydesmus (Spori- 

 desmium) exitiosum {var Baud) on carrot ; Helminthosporium gramineum 

 Eabh. causing withering of rye and barley leaves ; and Sporidesmium 

 putrefaciens Fuck, which attacks and kills the young heart-leaves of beet- 

 root. 



^v. Tubeuf, Botan. Centralblatt, xxi., 1885. 



^Sorauer, Sandbuch d. Pfianzenkrankheiten, ii. Aufi., p. 340; and Untersuch. 

 iib. die Bingdhrankheit u. d. Eussthau d. Hyacinihen. Leipzig, 187S. 

 ^N. Jersey Agrie. Exper. StoU, Report, 13, 1892. 



