JOURNAL OF AMMIlAl RESEARCH 
Vol. XXVI Washington, D. C., December 8, 1923 No. 10 
THE RED STAIN IN THE WOOD OF BOXELDER 1 * 
By Ernest E. Hubert,* Assistant Pathologist, Office of Investigations in Forest Path- 
ology, United States Department of Agriculture 3 
INTRODUCTION 
The red stain (pi. 2) so commonly met with in the wood of living 
boxelder trees (. Acer negundo L., syn. Negundo aceroides Moench.) has 
almost come to be recognized as a character in the identification of this 
species. Few have stopped to consider the cause of such vivid coloring, 
assuming in many cases that it was a normal character of the wood. 
During the years of 1921 and 1922 considerable attention was drawn to 
this wood and to the stain which characterizes it, in efforts to discover 
the cause of the stain and to find means of preventing it. The vivid col¬ 
oring is often attractive, yet due to its irregular distribution in the heart- 
wood and its presence, at times, in the sapwood and its less attractive 
shades and associated colorings, the wood so stained is often found 
objectionable. The wood of boxelder is used to a considerable extent 
for certain classes of furniture, interior finish, woodenware, cooperage, 
and paper pulp. In such cases the clear, creamy white color of normal 
wood is preferred. Therefore the disease was considered to be of suffi¬ 
cient economic importance to warrant an investigation of the red stain. 
THE DISEASE 
HISTORY 
The earliest and possibly the only reference to the red stain in box¬ 
elder, in so far as the writer could determine, was published in Germany 
in 1880 by Eidam, 4 who states that undoubtedly some unknown 
fungus is responsible for the stain. He notes that it is a very charac¬ 
teristic stain and that it can not be confused with the discolorations pro¬ 
duced in coniferous wood by Trametes pini and Fomes annosus (Trametes 
radiciperda ). 
The writer's attention was first called to this vivid stain in November, 
1920, when samples of boxelder from a Tennessee lumber company were 
received for examination. Microscopical examination disclosed the 
hyaline to slightly colored hyphae of an unknown fungus within the cells 
of the red-stained areas. Cultures on malt agar, made by using frag¬ 
ments of the red to pink colored wood, showed a white fungous growth 
attended by a pink discoloration of the agar, after incubation for seven 
days. In some of the tubes the white aerial mycelium seemed to dis- 
1 Accepted for publication June 25, 1923. 
a The writer is greatly indebted to Dr. C. D. Sherbakoff for naming the fungus discussed in this, paper 
and for furnishing a description of it with a text figure and colored plate. 
* In cooperation with the Forest Products Laboratory, United States Forest Service, Madison, Wis. 
4 Bidam, E. blaugrun gefajrbtes hcez von bieken ukd buchen und beut-bis carminroth 
gefarbtes von acer negundo. In Jahresber. Schles. Gesell. Vaterland Cult., Jahrg. 58 (1880), p. 188- 
189. 1881. 
Journal of Agricultural Research, 
Washington, D. C. 
ahy 
Vol. XXVI, No. 10 
Dec. 8, 1933 
Key No. G-34t 
71687—24 -1 
(447) 
