12 
BULLETIN 1037, U. S. DEPARTMENT OE AGRICULTURE. 
what similar examples, the blue color of thin milk, cigarette smoke, 
and the clear sky, wherein very fine particles are held in suspension 
in a transparent medium. 
OTHER FUNGOUS ORGANISMS CAUSING SURFACE DISCOLORA- 
TIONS IN GREEN TIMBER. 
In addition to the blue-stain fungi, there is another group, the 
molds, which commonly occur upon the freshly cut surfaces of green 
timber when stored under moist, warm, and stagnant conditions (PI. 
I, fig. 5 ; PL II, figs. 1 and 2). Molds are occasionally found growing 
vigorously upon timber in kilns (PI. I, fig. 4). This is especially 
noticeable when the atmosphere of the kiln is exceedingly moist or 
saturated and the temperature ranges 
from 90° to 110° F. 8 or from 110° to 
130° F. (Tiemann, SI, p. 186-187). 
Hedgcock (19) showed that the 
blackening and browning so common 
in the green sapwood of pine (Pinus 
sp.) , poplar (Populus sp.) , tulip (Liri- 
odendron sp.), red gum (Liquidarribar 
sp.), oak (Quercus sp.), maple (Acer 
sp.), and several other woods can 
often be traced to species of Graph- 
ium. He cites : 
A\M G. ambrosiigerum n. sp., on Arizona pine 
Hi M^ \M {Pinus arizonica Eng.). 
G. eumorphum Sacc, on wild red rasp- 
berry {Rubus strigosus) and related species. 
G. atrovircns n. sp., on red gum {Liquid- 
ambar styraciftua L. ). 
G. smaragdvnum (A. and S.) Sacc, on red gum {Liquidanibar styraciftua L.). 
G. rigidum (Pers.) Sacc., on red oak {Quercus rubra L.). 
G. aureum n. sp., on wh te pine {Pinus strobus L.). 
(7. album (Corda) Sacc, on beech {Fagus atropunicea (Marsh) Sndworth). 
Graphium spp. are perhaps best known by the upright, cylindrical, 
occasionally branched fruiting bodies 1 to 3 millimeters in height 
(fig. 3). These are often brown to black in color and bear at the 
tips comparatively large and, in many cases, confluent globules com- 
posed of masses of spores embedded in a mucuslike substance. These 
spore masses, though usually cream color, vary somewhat in hue, and 
in some species are tinged with gray, brown, green, yellow, or red. 
While these are the organs of fructification commonly observed, 
other types less conspicuous and bearing the so-called secondary 
conidia have been demonstrated in culture by Hedgcock (19). 
Fig. 3. — Fruiting body of GrapJvium 
sp. (After Munch, 31.) 
8 Information from the section of timber physics, Forest Products Laboratory, Madison, 
Wis. 
