354 



No doubt it is very common, but it may easily be missed as it is 

 very much like dust etc.; it covers the lower part of the stems and 

 the under-side of the leaves with a thin grey cover of mycelium. The 

 spores are 10—12 H X 6 ^. It seems not to hurt its host-plant, the 

 leaves will keep their fresh green colour even if attacked by this fun- 

 gus. American mycologists suppose this species to be genetically rela- 

 ted to Rhizoctonia (see Riehm 11), a supposition which I do not con- 

 sider to be sufficiently proved. 



Solanum tuberosum. J. Grenaa (Sloth), Herning (Claudi Westh see R 01 a ■'^^), 

 Esbjergl; Lyngby (21/7 99 K. H. see R 99 c 1^9). Solanum lycopersicum. Am. 

 Allegaarden (^s/s 05 Suhr see R 05 s). 



1653. Hypochnus basicola Rostrup 05 o. 



Tenuissimus, arachnoideus vel mucedineus, late effusus, junior griseo- 

 pallidus, denique flavido-rufescens, hyphis laxissimis, hinc inde ellip- 

 soideo-inflatis, cruciato-ramosis, anastomosantibus ; tuberculis mycelicis 

 sparsis, villosis, subglobosis, sclerotioideis. 



Its mycelium is very slender and covers the stems a little above, as 

 also a little below, the surface of the ground. It is very difficult to 

 tell if it is really this fungus which attacks the stems and makes them 

 decay. Rostrup has proposed four different species which, however, 

 come very close to each other, but he has not described all of them; 

 they seem to be closely related to Hypochnus solani and to Hyp. 

 cucumeris Frank. 



It is impossible to procure a fixed standard for judging of the limi- 

 tation of these species based only upon species from herbario. 



Hypochnus basicola Rostrup is found on Beta cult. S. Kirkesaaby ('/9 03 

 Teglbjerg), Raphanus sativus S. Landbohejskolen (May 02), Aster cult. J. Beder 

 (Henriksen June 03). 



Hypochnus Hellebori Rostrup 97 m "^ (nomen nudum), SylL 



Helleborus niger. F. Odense (Dec. 95 Ravens). 



Hypochnus resedae Rostrup in herbario. 

 Reseda odorata. S. 0sterbro (L0ve '"/b). 



Hypochnus carotae Rostrup in herbario. 



Daucus carota. J. Christiansholm (Aug. 88); S. Lyngby (M. L. M. Aug. 10). 



Hypochnus cucumeris Frank, Syll. VI ^". 

 Cucumis sativus. S. Svenstrup C^/b 03). 



1654. Hypochnus sulphureus (Fries) Schroet., Syn: Corticium 

 sulph. Pers., Fries Epicr. ^^\ Syll. VI «'^ Thelephora sulph. Fries S. M. 

 I ''=^ Svovlgul Barksvamp (R 04 a «'). 



