254 Diseases of Greenhouse Crops 



Fungi on the Ericas 



Ericas are apparently very hardy plants. The 

 only fungus known to cause a disease on greenhouse 

 plants is Stemphylium ericoctomim Br. and De By. 

 The other recorded fungi are as follows : Cystospora 

 ericeti Sacc, Sporonema ohturatum (Fr.) Sacc, 

 Trichosporium fuUginosum Karst. 



Ferns 



Cultural Considerations, Ferns are propagated 

 by spores, or by division of the clumps. The spores 

 are sown on garden loam over which half an inch of 

 fine sphagnum has been placed. The spores are 

 scattered evenly, and after being sprinkled with 

 water are covered with a glass. In the division of 

 the crowns, they should be planted and kept in a 

 cool house or frame until they make a good start. 

 Most greenhouse ferns thrive best in a temperature 

 of 60 to 65 degrees F. 



The following ferns are usually grown on a com- 

 mercial scale : Adianthum cuneatum and A. gracilli- 

 num. Adianthum farleyense seems among the best 

 for decorative purposes. Pteris serrulata is also ex- 

 tensively grown. In large conservatories the tree 

 ferns, especially Alsophila australis, is very much 

 in favor. Of the ferns propagated and sold for 

 dwelling house purposes may be mentioned the sword 

 fern, Nephrolepis exaltata. The latter can stand 

 the atmosphere of a dry room better than any other 

 fern. 



