Kelley — 114 — Mycotrophy 



(1884) made a detailed study of various J uncus plantlets and found 

 them inhabited by a fungus and swollen into tubers the size of which 

 depends on activity of the rush. The fungus is present only in radially 

 enlarged cells of the periblem where it forms coils of reagent-resisting 

 hyphae, and surrounds the nucleus; or hyphae penetrate to other 

 cells. As in rust fungi, the hyphae are surrounded by a cellulose layer 

 that is continuous with the membrane of the penetrated cell. Spores 

 are formed by the fungus, which assume a barrel-shape and become 

 surrounded with a thick dark wall. In winter, the mass of the former 

 tuber in wet earth is full of ochre-yellow spores which germinate 

 naturally in February. The fungus is considered to be Entorrhisa 

 cypericola, placed in the Tilletiaceae. Grutter said that in /. Tenageia 

 the fungus encloses tip of root, penetrates epidermis and forms 

 special structures in it. The stele is much reduced. Lagerheim 

 (1888) described E. digitata from /. articulatus in Switzerland. The 

 roots were deformed into root galls and contained an abundance of 

 yellow spores, and the fungus was extracted with difficulty. In the 

 Black Forest, /. articulatus bore mycodomatia in very sandy and not 

 too wet soil but they were absent from moor and loam soils, occurring 

 in the uppermost soil horizon. 



Molinia: — This grass forms a "molinetum" on sterile sands of 

 northern Germany and elsewhere, its rhizomes and interlaced roots 

 acting as sand-binders. It overwinters as swollen basal nodes while 

 the roots are endotrophic, never ectotrophic. A line drawing indicates 

 fungal coils in inner cortical cells and a possible "sporangium", per- 

 haps a vesicle. Data are presented on N content of tuberous rhizomes 

 and seeds. Plants were grown for three months in culture solution 

 and sand, and one plant at the end of the experiment was found with 

 fungus-free root system, while its rhizome-base was filled with starch. 

 Hence grasses must be examined in considerable numbers to determine 

 true extent of infection for some, like Molinia, may be facultatively 

 mycotrophic (von Tubeuf, 1903). 



Gyperus: — Magnus (1879) described a fungus, Schinsia cyper- 

 icola, living in roots of C. flavescens. Through its activity the root 

 swells into a simple tuber or, if the roots branch, into a branched 

 tuberous body. In Schoenus ferrugineus there are mycodomatia 

 containing normal fungal hyphae (Renner, 1935). 



Asparagus: — Root nodules of Asparagus have been described in 

 Japanese by Fujita (1940). 



