16 THE "bluing and THE "RED ROT OF THE PINE. 



In spite of numerous investigations, the causes of the green color 

 and its relation to the wood remained comparative] 3^ obscure until 

 recenth', when Vuillemin published an extended account" showing 

 that one form of the green color was due to the growth in the wood 

 of one of the Discom3'cetes, Ilelothnn xruginosum. Vuillemin men- 

 tions a number of other fungi which have been described as causing 

 the green color, among others, PropoUdium atrocyaneum Rehm, on 

 wood of the poplar; JVxvla ceraginosa Rehm, on the tans}^; and 

 Fusarium peruginoHuni Delacroix, on potato tubers. 



Without going into details, Vuillemin established the fact that the 

 green coloring matter, called xylindeine, is formed by the hyphse of 

 Helotium sdruginosum, and that the presence of these green-colored 

 hyphfe gives the green color to the wood. The wood fiber itself 

 remains colorless. The xylindeine is soluble in alkalis and can readily 

 be extracted. The wood fiber is not destroj^ed, but remains intact. 

 The name "green deca)^" is therefore incorrectlv applied, for the 

 green wood is in no sense decayed. This is an interesting fact, for it 

 will be remembered that the same has been said of the "blue'' wood. 

 A more detailed comparison of the relation of this green coloring mat- 

 ter and the fungus forming it to the coloring matter in the ''blue" 

 wood will be published in another paper. 



The blue stain of coniferous woods is a familiar defect in the United 

 States, particular!}^ in the South, where freshly sawed lumber, 

 especially shingles and lath, is affected during the moist warm weather 

 of April, May, and June. The blued lumber is considered as a low- 

 grade material, and many precautions are taken by Southern manufac- 

 turers to prevent loss. A full account of this trouble and a discussion 

 as to its cause and methods for its prevention are now in preparation. 



In Europe the blue color of pine wood was first noted b}^ Hartig,* 

 who refers brieflj^ to the fact that a fungus ( Ceratostoma piliferuTn 

 (Fr.) Fuckel), is the cause of bluing in coniferous wood, especially of 

 pine trees which have been weakened by caterpillars, and of firewood. 

 He states that the hyphee of this fungus, which are brown, grow rap- 

 idly inward into the trunk through the medullary raj^s and that they 

 avoid the heartwood, probabl}" because of its small water content. 



The blue color of coniferous wood in this country is probably caused 

 by the same fungus referred to by Hartig, although it seems necessary 

 to refer to it under a different name {Ceratostomella pilifera (Fr.) 

 Winter). 



« Vuillemin, Paul. Le Bois Verdi. (Bull, de la Soc. d. Sciences de Nancy, Ser. II, 

 16: 90-145; 1898. Ipl. ) References to earlier works on the green color are given 

 in this paper. 



6 Hartig, Robert. Lehrbuch der Pflanzenkrankheiten, 1900, pp. 75 and 106. (See 

 also earlier editions of the Lehrbuch fiir Baumkrankheiten; see also Frank, A. B., 

 Krankheiten der Pflanzen, 1: 107, 1895.) 



