SAP-STAIN, MOLD, AND DECAY IN GREEN WOOD. 13 
Other fungi mentioned by Hedgcock (19) as blackening wood are: 
Alternaria tenuis Nees., Stachybotrys alternans Bon., Aspergillus 
niger, Chaetomium sp., Stemonitis sp., Gliocladium sp., Hormoden- 
dron sp., Ilormiscium sp., and Cladosporium sp. The apparent dis- 
coloration in these cases is due either to the presence of colored 
hyphae in or upon the surface of the wood or to a luxuriant super- 
ficial growth of colored spore masses. In no case is it due to the* 
secretion of any pigment which is absorbed by the wood. 
Hedgcock (19) names three other species — Penicillium aureum 
Cor da, Penicillium roseum,, and a Fusarium sp. formerly included 
under Fusarium, roseum — which, due to the secretion of soluble pig- 
ments, actually stain the wood red, purple, or yellow, according to 
the alkalinity or acidity of the medium. These stains are superficial, 
however, and readily dress off when the lumber is planed. Many 
other molds grow readily upon green sapwood and give the timber 
a displeasing appearance, though they cause no deterioration in 
the strength of the wood. From the material collected by the writer 
and sent to the Madison laboratory there have been isolated over 40 
distinct species of fungi. With the exception of species of Ceratosto- 
mella and Graphium, together with a species of Fusarium which was 
identified by Dr. Mabel M. Brown, graduate student at the Uni- 
versity of Wisconsin, as F. arthrosporioides, this number consists of 
fungi popularly known as molds. The determination of the molds 
was made by Dr. Charles Thorn and Miss Margaret B. Church, of 
the Bureau of Chemistry, United States Department of Agriculture. 
They are listed below : 
Aspergillus flavus series. Penicillium asperulum or puoerulum. 
Aspergillus niger. Penicillium brevicaule series. 
Aspergillus repens. Penicillium commune. 
Aspergillus versicolor group. Penicillium divaricatum. 
Cephalothecium roseum. Penicillium lilacinum. 
Citromyces sp. Penicillium lutcum. 
Cladosporium sp. Penicillium purpurogenum. 
Clonostachys sp. Penicillium roqueforti. 
Gliocladium sp. Penicillium rugulosum. 
Haplograpliium sp. Penicillium solitum. 
Monilia sitophila. Syncephalastrum sp. 
Mucor sp. Trichoderma sp. , , 
Oidium sp. 
The great variety of genera and species here noted contains many 
earth dwellers and indicates that the molds commonly found upon 
green timber, especially during storage and transit, are for the most 
part soil forms whose spores have by accident fallen upon the 
moist surfaces of the sapwood and there found the conditions favor- 
able for development. 
It has generally been supposed that the growth of mold on wood 
is confined mainly to the surface or, at the most, to the superficial 
