Order Hymenomycetes. Tribe Pileati. 



Plate LXIV. 



POLYPORUS ULMARIUS, .y....% 



Elm tree Poly2iorus. 



Gen. Cltar. Hymenium concrete with the substance of the pileus, consisting of sub-rotund pores, with thin, 

 simple, dissepiments. Name n-oXis, many, and mpos, a j'ore, in allusion to the numerous pores of the hymenium. 



Spec. Char. Polyporus ulmarius. Pileus between fleshy and corky, eff'used with an obtuse occasionally 

 free margin ; forming a new stratum every year, so that a vertical section gives several distinct layers of pores and 

 flesh alternating with each other ; zoneless, smooth, whitish ; pores minute, tawny salmon-colour. Flesh white. 

 Substance, when dry, hard and corky. 

 Polyporus ulmarius. Fries, Berkeley. 

 Boletus ulmarius, Sowerhy. 



Hah. On aged elms, often close to the ground. Biennial or perennial. Not common. 



Sowerby appears to have been the first to notice this fungus, and he describes it so gvapliically, that 

 no apology is needed for giving his own words : it would not be easy to improve upon them. " Boletus 

 ulmarius may be found on old or rotting elms {ulmus campestris) thriving in damp weather most part of 

 the year. It is a very solids tough, unshapen mass, often very large, commonly attached by the back so as 

 only to show the edge of the rugged pileus. The pores are very fine, frequently in many strata under each 

 other of various lengths. I found a large mass spreading full three feet, last autumn, in the hoUow of an 

 old elm in St. James's Park, forming a grotesque kind of ceiling of different tints." On this text we may 

 note, that Sowerby appears to have found the plant only when mature ; the various layers of pores, indica- 

 ting various periods of growth, prove this, as well as his speaking of its being " very solid and tough." In 

 its first state it must be effused very rapidly, and is of so soft and juicy a consistency as to embrace grass, 

 ivy, tmgs ; in fact every obstacle to its spreading is involved in its white downy substance, as it flows in 

 undulations, like inspissated sap ; in wet weather and in situations abundant in moisture, it attains a large 

 size, without any determinate configuration ; the salmon-buff pores are not visible at first, but a few form 

 here and there as the substance hardens ; then comes a fresh supply of moisture inducing a fresh formation 

 of pileus, again hardening and forming pores, and so it goes on ; two or three increments take place in one 

 year, guided entirely by the moisture afforded, the entire period of growth is perhaps extended through 

 several years, but the particular portions of pileus first developed grow dry, pallid, are covered with green 

 Algee, and are in fact only skeletons, inert and lifeless ; a gradual decay takes place ; therefore, although the 

 mass is perennial, the growths composing it are annual, for they are not in perfection for a longer period. 

 In Kent, where elm is the weed of the soil, and the hedge-rows are often composed of it pleached, the old 

 stools afford frequent specimens of P. idmarim, where repeated wounds of the hedge-biU cause the sap to 



