80 NINTH REPORT. 



FOMES PINICOLA FR. AND ITS HOSTS. 



L. H. Pennington. 



It Avas the pleasure of the writer to spend the summer of 1900 with Mr. C. 

 H. Kauffman in the study of the fungus flora of Northern Michigan. We 

 left Ann Arbor July 7th and went directly to Sault Ste. Marie where we re- 

 mained ten days. We then spent five weeks in Keweenaw Peninsula with 

 Houghton as our principal station, one week at Munising, and two at Mar- 

 quette. On our return we stopped for a few days in the vicinity of Petoskey. 



At all the places which we visited the forests consist of both hardwoods 

 and conifers, either growing together or in societies* not very widely separated 

 from each other. The principal hardwoods are the Hard Maple, Beech, 

 Yellow Birch, White Birch, Red Oak, Balsam, Poplar, American Aspen, 

 Black Ash, and the Hop-hornbeam. Of these the beech was not found at 

 Houghton or Marc{uette, but it is very abundant at the other stations. The 

 ]3rincipal conifers are the Hemlock, the White, Norway, and Jack Pines, 

 White and Black Spruce, the Balsam Fir, the White Cedar and the Tamarack. 

 The Norway and Jack Pines were seldom seen except at Marquette. 



Although hardwoods and conifers were often found growing together, the 

 same fungus was seldom found upon both. Fomes snlicinus (Pers.) Fr. was 

 found upon Hemlock and Balsam Poplar at Marquette; Poria subacida Pk. 

 upon Hemlock, Spruce and American Aspen; Polyporus sulphureus Fr. upon 

 Red Oak and Hemlock; Polyporus resinoms Fr. upon Maple and Hemlock. 

 The most notable instance, however, was the occurrence of Fomes pimcola Fr. 

 upon the hardwoods and conifers. 



Fomes pinicola Fr. was found to be the most common of the larger fungi 

 that infect the conifers. At practically every place that we visited it was 

 found upon Hemlock, White Pine, Spruce and Balsam Fir. At Petoskey 

 it was found upon Tamarack also. In the vicinity of Ann Arbor the Tama- 

 rack seems to be its only host. The fruiting bodies were almost always 

 found upon dead trunks, very often after the wood had become much decayed. 

 When upon stumps or standing trunks they were observed to be near the base 

 usually only a few inches above the ground. Upon prostrate trees they 

 were scattered along the trunk and everywhere growing most abundantly in 

 moist situations. 



The pileus is usually concentrically sulcate (sometimes even) and zonate. 

 The marginal zone is yellow varying from white when the annual growth begins 

 to a dark yellow or red by the time the next annual growth appears. The 

 second zone is a dark red and the rest of the pileus is black. The shape, 

 which depends largely upon the rate of growth, varies from a hoof or cushion 

 shape when growth is slow, to applanate forms when growth is rapid. The 

 substance and pores vary from white to ochraceous or straw color. The 

 pores, which are very small, are not closed or stuffed in young stages so that 

 it is difficult to determine whether a specimen is mature or not. It is im- 

 possible to determine the condition of a plant in this respect after it has been 



^ Davis, C. A., Formation, Character and Distribution of Peat Bogs in Northern Michi- 

 gan, Report of State Geological Survey for 1906, p. 191. 



