Dec. 8 , 1923 
The Red Stain in the Wood of Boxelder 
451 
and the loss suffered is in proportion to the reduced price. For uses 
where bright stain-free stock is required, the red-stained wood is rejected. 
However, the stained stock is used for many purposes where the dis¬ 
coloration meets with little or no objection, or where it is covered or 
painted. The fact that this fungus is often associated with decay- 
producing organisms in the heartwood of boxelder should cause some 
hesitation in using stained stock for purposes requiring sound material. 
THE CAUSAL ORGANISM 
TAXONOMY 
The causal organism has been isolated repeatedly in pure cultures by 
using fragments of the red- 
stained wood. Pieces of 
wood taken from the stained 
areas, the surfaces thor¬ 
oughly sterilized by wash¬ 
ing in mercuric chloride, 
1-1,000, and then washed 
in distilled water, when 
placed in sterilized moist 
chambers invariably de¬ 
veloped a white to pinkish 
mycelium in the red-stained 
areas adjoining the un¬ 
stained wood and to a less 
extent in the remaining 
red-colored areas. Spores 
collected from this myceli¬ 
um proved to be typical of 
the genus Fusarium. The 
various types of spores ob¬ 
tained on the malt, prune, 
and oatmeal agars by trans¬ 
fers from the primary cul¬ 
tures, gave additional proof 
of its generic identity. Cul- v 
tures on malt agar and on 
Oatmeal agar were sent to Fig. I. —Fusarium negundi Sherb. A.-— Sporodochial conidia 
Dr C D STif»rhalcnff Pv- from 30-day-old culture on oat agar plus 3 per cent glucose- 
ui. u. oncxudKun, ma itose, in Petri-dish. B.-Free conidia from 3-day-old 
periment Station, Univer- culture on corn-meal agar, in Petri-dish. Magnified 1,000 
Sity of Tennessee, who diameterS - Dr. C. D. Sherbakoff. 
kindly determined the species and submitted the following description of 
the causal organism : 
Fusarium negundi Sherbakoff (new species). 
Sporodochial conidia o to 5-septate; o to 2-septate few, 3 to 5-septate 
common, 5-septate most numerous and measure 4.25 x 38.5 (4-6 x 34-42) 
/*; the spores are gradually attenuate toward the apex, pedicellate, some¬ 
what more distinctly curved toward apex. Conidia borne singly on mycel¬ 
ial branches, few, 0-3-septate, ventrally nearly straight, apedicellate, api- 
cally attenuate. Aerial mycelium on most media in test tubes and in plates 
rapidly growing, even, fine, from white to carmine; substratum, in plates 
on agars with glucose, of carmine color. Large plectenchymic bodies 
(ps^udo-sclerotia) common on oat agar. The sporodochial conidia much 
