292 



pecially true during raiuy seasons. Some species are found upon the dead 

 barli of trees and branclies which are not in an advanced stage of decay. 

 Others are usually found uiwu decorticated wood which is still sound. 

 Still others seem to prefer wood which is very rotten. Occasionally a 

 species is found which seems to flourish equally well under any or all of 

 these conditions. Especially is this true of certain species which grow 

 in great profut^ion both on souiul bark and decorticated wood. 



It is* thus evident from the very nature of this group of fungou.s 

 plants that they are of very litth\ if any, economic importance. Since 

 they arc not iiarasitic. they never cause the death of living plants, and, 

 aitiiough true to fungous natui-e, they aid in the decay of timber already 

 dead, yet, because of the fact that they thrive only in the forest, they 

 are not destructive of tinilter which has Imumi promptly removed to its 

 propi-r i)lace of use. The chief interest, then, which attaches to them is 

 a scientific one. ^lost .species of Ilypoxylon are large and conspicuous 

 hi coniiiMrisoii with must otlu'r genera of Pyrenomycetes, and therefore 

 they attract the attention of the collector. It is i)erhaps this character- 

 isiiv- more than any other which makes them interesting to the student 

 o!' fungi. 



The Ilypo.xylons develop late in the season, passing through the 

 couidial stage during the sununer or early autunm. The perfect stage 

 follows the conidial and arrives at maturity sometime during the fall or 

 early winter. The time foy collecting mature specimens, then, is during 

 the late autuuni or early winter. They persist throughout the winter, 

 however, and may lie collected in good condition until the warm weather 

 of .'•priug comes, when they begin to disintegrate rapidly. 



In attempting to make a key to the species of Hypoxylon a great 

 dillicnlty is encountered. Perhaps there are few genera of fungi, or even 

 nf .-my group of plants, which offer more difficulty along this line than 

 the genus under cousideiation. In the first i>lace the genus itself is not 

 s(t off from all other genera by distinct and unmistakable characters. 

 !"or example, it would take an expert to distinguish with accuracy be- 

 tween some sjiecies of Xunnnularia and certain of the Hypoxylons. This 

 lack of reliable marks of identity is even more evident when it comes to 

 distinguishing between tlie various species of Ilypoxylon. 



Most investigators who have worked with this genus have attempted 

 U) divide it into groups of doubtful extent on the basis of the form and 



