INJURIES INDUCED BY PLANTS 117 



disease which is due to an allied parasite, Hysterium bracJiy- 

 sporum. I am not yet able to determine whether Hysterium 

 laricinum, which has been observed in great abundance 

 on larches in certain districts of the Alps, is also a true 

 parasite. 



The sub-family of the Pezizece is to be distinguished by cup- 

 shaped or saucer-shaped sporophores, which produce the 

 hymenial layer free on the upper surface. 



PEZIZA (HELOTIUM) wiLLKOMMH 1 * 



The fungus which induces the larch-blister is the cause of one 

 of the most destructive and widely distributed diseases of the 

 larch. It was first described by Willkomm, 2 who, however, 

 made a mistake in its identification, and called it Corticiim 

 amorpJium. 



Corticiim, in fact, bears only a superficial resemblance to 

 Peziza, and belongs to the Basidiomycetes. On the strength of a 

 macroscopic similarity, also, it was next said to be Peziza 

 calycina, till I recognized that in this fungus we had to do with a 

 new and still unknown species. The ascophore is at once 

 distinguishable from that of P. calycina by its very short cup- 

 stalk. So much by way of explaining the regrettable confusion 

 of names. 



The larch is a forest tree which thrives splendidly throughout 

 the whole of Germany, suffering but little from frost, at least 

 not more so than other indigenous trees. Originally, how- 

 ever, its distribution was confined to high Alpine regions, 

 because only there could it offer successful resistance to its 

 enemies. Amongst these enemies are to be classed a number 

 of insects, notably the Larch moth, ColeopJiora laricella. This 

 insect is also found in Alpine regions to a considerable height 

 (over 4,000 feet), and so widely is it distributed, and so 



1 R. Hartig, Untersuchungen aus dem Forstb. Inst., I. pp. 63 88. 



- Willkomm, Mikroskopische Feinde des Waldes, II. pp. 167 et seq. 



* [Though often overlooked, this fungus is quite common on the diseased 

 Larches in England and Scotland, with all the characters and relations to the 

 "blisters" described by the author. Phillips,*?/, tit. p. 241, gives it as 

 Lachnella calycina, and makes no note of its relation to the disease. ED.] 



