Rhizoctonia lanuginosa Bernard (1909.)
FORM-GENUS Rhizoctonia
 

Etymology: The specific epithet means "hairy"
 
Synonyma: (? =) M. R. 18 (Burgeff 1936., p. 135)
Telophase:  Unknown.
Rhizoctonia lanuginosa Bernard (1909.)
Isolate M. R. 18 by Burgeff
Diagnosis:
  
"Les cultures sur les milieux nutritifs riches prennent un aspect cotonneux par suite du développement précoce sur le voile d'un duvet blanc de filaments aériens. Les filaments moniliformes, á articles allongés, s'anastomosement et forment des sclérotes compacts, charnus, á surface mamelonnée, d'abord blancs opalescents, prenant tardivement une teinte orangée ou ocracée pâle; les sclérotes sont peux nombreux; leur taille est variable, le plus gros dans mes cultures atteignaient la grosseur d'un pois. L'enroulement du mycelium en pelotons peut se prolonger pendant de nombreux tours." 
(Quoted from Burgeff 1936., p. 141)
 
  According to Burgeff (1909., p. 209.): "Wiederholt isoliert aus Odontoglossum grande." 
This isolate still survived in the sixties as CBS 125.08.
 
  Another point to note: "Rhizoctonia lanuginosa lässt sich unter unsere Pilzen nicht auffinden." (Burgeff, ibid., p. 210.)
 
   "In general the fungi with potentialities little suspected previously, have been found during the past fifty years to be highly advantageous material for the study of many significant aspects involved in the problems of sex and have revealed complexities of behavior beside which the human patterns reported by Kinsey, Havelock Ellis, Kraft-Ebing, Malinowski and others, show a limited and naive simplicity."
W. H. Weston: Mycology during the last fifty years.
American Journal of Botany 44:82-87.(1957.)
   "Too often, perhaps, we visualize a taxonomic system as resembling a brick wall, each brick a taxon, and each taxon firmly cemented in its place. Of course, someone periodically pulls down and rebuilds the wall, employing some of the original bricks (properly cleaned) and adding new ones where appropriate. Other walls are so poorly fabricated that they may fall of their own weight even when no one touches them, and occasionally they fall on their builder."

L. Constance: Plant taxonomy in an age of experiment.
American Journal of Botany 44:88-92.(1957.) 

Bibliography
Bernard, N.:

L'evolution dans la symbiose. Les orchidées et leur champignons commensaux.

 
Ann. Sci. Nat. (Bot.) 9me Sér. 9:1-196.(1909.)
 
Rhizoctonia lanuginosa, Rizoctonia mucoroïdes and Rhizoctonia repens were described in this paper.
An attempt was also made to alter the microsytematics of Orchidaceae on the basis of mycotrophy.
Burgeff, H.:
Die Wurzelpilze der Orchideen, ihre Kultur und ihr Leben in der Pflanze.
 
G. Fischer, Jena, pp. 1-220, ( 1909 .)
Burgeff, H.: Samenkeimung der Orchideen und Entwicklung ihrer Keimpflanzen.
Mit einem Anhang über praktische Orchideenanzucht.
 
Verlag von Gustav Fischer, Jena ( 1936.)