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, tliick, sharp-pointed teeth of a Hght-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 gi'owth. In a growing condition the 

 outer zone is white or brown, context solid, and of a Mars-orange 

 to orange-rufous color.' The minute characters of the fruiting organ 

 are: Spores hyaJijie, broadly ellipsoid, 4 by 6 )u, teeth covered with 



Fig. 1. — Sporophore of Echinodonihim tinctorium on hemlock. Bottom view, showing fresh hymenium 



or spore-producing surface. 



short colorless setae or microscopic spines. The hymenium of the 

 young growing fungus is by no means toothed in the beginning 

 but is typically dsedaloid, 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. Tlie fungus 

 is likewise employed by the Indians of Alaska for medicinal jDurposes 

 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 Kidgway, Kobert. Color Standards and Color Nomenclature, pi. 2. Washington, D. C., V.)V2. 



