8 BULLETIN 212, U. S. DEPARTMENT OF AGRICULTURE. 



The writer finds this mistletoe to be the cause of serious damage to 

 the jack pine at its most western extension or where it approaches the 

 zone of the lodgepole pine in the north. 



SAPROPHYTIC FUNGI. 



Aside from the previously mentioned wood-destroying species, 

 which in many cases continue alive after the death of the host/ the 

 usual strictly saprophytic fungi of coniferous woods are found on cut 

 or fire-killed jack pine. Ceratostometla pilifera Fr., the blue-stain 

 fungus, appears very rapidly after the death of the tree. In moist 

 situations, species of Auricularia and Dacryomyces are surprisingly 

 abundant, but can be of little importance, as the mycelium does not 

 penetrate the wood to any appreciable distance. The first fungus 

 of importance is Polystictus abietinus Dicks. This is a sap-rotting 

 species and is seldom absent from fire-killed trees after the second or 

 third year. Second in importance is Lenzites sepiaria Fr., which 

 works both in the sap and in the heartwood and usually appears on 

 the fallen trunks after they have lain for three or four years, following 

 up the first-mentioned fungus. The Lenzites appearing on jack pine 

 is invariably the true, small, thin-fruited form, with radiating gills. 

 Lenzites sepiaria is as easily recognized by the orange-yellow color 

 of its growing margin as the young, growing Polystictus abietinus is 

 by its beautiful purple tinge. Fomes ■ pinicola Fr. has very little to 

 do with the decay of fallen jack pine. This fungus has not been 

 found to be very common. Polyporus palustris Berk, and Curt, 

 occasionally appears, but is more common on dead Norway pine. 

 Fomes carneus "Nees" very rarely occurs on jack pine. Lentinus 

 lepideus Fr., Polyporus sulphur eus Fr., and Trametes sepium have 

 been collected by the writer on dead jack pine, but they are very 

 rare. Resupinate Thelephoraceae occur only in the moist stands of 

 mixed species. Those which may be considered of importance in 

 the decay of fire-killed timber in the forest are Corticium byssinum 

 (Karst.) Burt., C. sulphureum Pers., C. galactinum (Fr.) Burt., 

 Coniophora olivaceae (Fr.) Bres., and Peniophora globifera E. and E. 

 A yellowish white Poria which goes under the name of P. subacida 

 Peck is occasionally found on fallen jack pine in Minnesota. This 

 fungus has been observed by the writer in a fruiting condition on old 

 boxes and barrel staves made from newly felled living trees. This 

 indicates its probable parasitism on jack pine in the living forest. 



i This is a fact that is not generally appreciated, and on it depends the solution of some very important 

 pathological problems in the forest. Vigorously growing sporophores of Trametes pint springing from 

 original infections in the living tree have been collected from a fallen western larch which had lain on the 

 ground for more than 100 years. This was determined by the age of a western red cedar growing astride the 

 fallen trunk. Practically all the more serious wound and root fungi of the genera Trametes, Fomes, Poly- 

 porus, and Agaricus in moist situations continue alive indefinitely after the death of their hosts. 



