THE BRACKET FUNGI. 



The plants known as Bracket or Shelf 

 Fungi are familiar objects to every lover 

 of nature who frequents our groves and 

 forests. Beginning as small, slightly 

 elevated protuberances, or flat orbicular 

 patches on the bark of a dead tree trunk, 

 log or stump, they gradually increase in 

 size and assume more or less definite 

 shapes. Some never attain a breadth of 

 more than a third of an inch, while 

 others may ultimately obtain a width of 

 nearly a foot and one-half, and project 

 fully one-half that distance from the sur- 

 face of the matrix. The most common 

 form, perhaps, is that of a semi-circle, 

 the fungus being more or less flattened 

 and attached by its straight edge to the 

 log or stump. 



The species upon the under surface of 

 which pictures are often etched (Fomes 

 lucophaeus) is a familiar example. This 

 species occurs on logs and stumps of all 

 kinds, throughout a large portion of the 

 United States. Other kinds, beginning 

 as separate brackets, become united by 

 their edges so as to form continuous 

 strips or ribbons which may extend a 

 yard or two along a fallen log. Still 

 others become imbricated, one above an- 

 other, so that the side of a dead standing 

 trunk may be entirely covered with pro- 

 jecting shelves or brackets for several 

 yards, and the series may wholly encircle 

 the trunk. Other species rarely assume 

 a definite bracket form, but remain as flat 

 areas attached to the bark and are called 

 resupinate. Sometimes the edges are 

 upraised so as to form cup-shaped 

 growths. Several kinds are so thickened 

 that they nearly resemble a horse's hoof 

 in form, while a few others, although 

 classed as "brackets," are merely amor- 

 phous masses appearing in a knot hole 

 or -^vounded place in a log or stump. 



All of these conspicuous forms are only 

 the fruiting receptacles of the plant. 



Their nourishment is provided by means 

 O'f slender, almost invisible threads which 

 permeate the tissues of the log or tree 

 upon which the fungus grows. These 

 threads or filaments are technically 

 known as mycelia, and have the power of 

 breaking down the complex tissues of the 

 bark and wood of the host upon which 

 they grow and converting them into food 

 for the fungus. By the continued activity 

 of these mycelia, a log may be wholly 

 reduced to decay without the production 

 of any brackets or fruiting receptacles. 

 The conditions under which the brackets 

 appear are as yet imperfectly understood, 

 but as they constitute the only visible 

 portions of the fungus, their forms, col- 

 ors and other physical characters are used 

 as the basis of scientific classification. 



All of these fungi reproduce by means 

 of spores which are borne upon some 

 part of the fruiting receptacle. It has 

 been found that the spores of the bracket 

 fungi are produced : 



a. On plates or gills on tne under side 

 of the fungus. 



b. In the interior of tubes lining the 

 under surface of the fungus. 



c. On an even surface, usually on the 

 under side of the fungus. 



The fungus which we illustrate (Ster- 

 eum fasciatum) occurs on the trunks of 

 various trees in Canada, the United 

 States and in Mexico. The plants grow 

 in tufts or clumps. The pilei or recep- 

 tacles are leathery and thin. At first, 

 they are plain; later, they are often re- 

 curved at the edges. They are villous, 

 with brown, shining zones, and the bases 

 are narrowed and substipitate. The hy- 

 menium or fruit-bearing surface of each 

 plant has a pallid brick color, sometimes 

 with reddish or lilac tints. The speci- 

 mens figured are proliferous ; that is, 

 new pilei arise from the edges of those 

 of the preceding season. 



Will Sayer Moffatt. 



143 



