4 BULLETIN 722, U. S. DEPARTMENT OF AGRICULTURE. 
The chief gross character by which the fruiting organ of the fungus 
may readily be recognized is a hymenium consisting of numerous 
firm, thick, sharp-pointed teeth of a light-brown color (figs. 1 and 2). 
The upper surface is almost black in old specimens (figs. 3 and 4), 
usually of a lighter color when young, and concentrically zoned, 
each zone representing a year’s growth. In a growing condition the 
outer zone is white or brown, context solid, and of a Mars-orange 
to orange-rufous color.t The minute characters of the fruiting organ 
are: Spores hyaline, broadly ellipsoid, 4 by 6 u, teeth covered with 
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Fig. 1.—Sporophore of Echinodontium tinctorium on hemlock. Bottom view, showing fresh hymenium 
or spore-producing surface. 
short colorless setze or microscopic spines. The hymenium of the 
young growing fungus is by no means toothed in the beginning 
but is typically dedaloid, a character often misleading to the unin- 
itiated when the interior has not been examined. 
On account of its tinctorial property, the powdered fungus mixed 
with tar or oil is used by the Indians as a war paint. The fungus 
is likewise employed by the Indians of Alaska for medicinal purposes 
and as a dye. For the latter reason it has received the common 
name of Indian-paint fungus. Since an oily alkaloid has been 
detected by the analysis of the fungus, there is a possibility of its 
1 Ridgway, Robert. Color Standards and Color Nomenclature, pl. 2. Washington, D. C., 1912. 
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