248 POLYPOREAE OF SOUTH AFRICA. 



be either central, excentric or lateral, and this, too, is a character 

 fixed in some and variable in others. In a very few species the 

 stipe arises from a tuber or sclerotium. 



The sporophores are either annual or perennial. In some of 

 the annual species the sporophores may survive a second season 

 (e.g., P. gilvus; J', fruticurri). 



In consistency the sporophores of the different species show 

 considerable variation. They vary from spongy forms like 

 P. fruticum, through soft fleshy forms such as P. sulphureus, to 

 fibrous and flexible forms like P. versicolor, and extremely hard 

 and woody forms such as the majority of Forties spp. 



In shape, considerable variation is found. Some are circular, 

 others semi-circular, fan-shaped, hoof-shaped or flat, funnel-shaped, 

 ear-shaped, etc. In distinguishing the different shapes various 

 terms are used such as ungulate (hoof-shaped), dimidiate (semi- 

 circular), infundibuliform (funnel-shaped). 



Surface of the sporophores. The sporophores show striking 

 differences in surface modifications. Thus, we find species like 

 Forties applanatus and others with a hard, horny, encrusted sur- 

 face, and in some of these the crust has the appearance of being 

 covered with varnish (e.g., P. hind us, ]' . nigro-lucidus, and 

 others). In others the surface hyphae end loosely and form hairs 

 of various types and descriptions. The surface may be smooth, 

 furrowed, zoned, wrinkled, dotted with tubercles, and in some, 

 rough, with appressed fibrils. 



The sporopiiore can for our purpose be considered as composed 

 of two main regions (a) the layer or layers of tubes termed the 

 hymenophore and (b) the region above this pore layer known as 

 the flesh or context, of the sporophore. 



The Context or flesh. The colour of the context varies for 

 different species, and this character is used for separating the 

 species. In consistency the context also varies considerably, but is 

 fairly constant for each species. In many the context is hard and 

 woody (e.g., majority of species of Fomes) ; in others, again, it 

 may be corky, cheesy, fleshy, tough or fibrous. In a few it is 

 spongy (e.g., V . fructicum) and in some it is floccose (e.g., 

 P. colossus and others). In some the context becomes very fragile 

 when the fungus is dry (e.g., P. immaculatus) . 



The Hymenophore. The term hymenophore is used to denote 

 that part of the fructification on which the spore-bearing region 

 or hymenium arises. Used in this sense it would include the 

 interior tissue of the pores and the tissue at the base of the tubes. 

 Since the poroid character of the hymenophore separates the 

 Polyporeae from related families and subfamilies, it is taxonomi- 

 cally an important region, the nature of the pores or tubes also 

 being used in distinguishing different genera of the sub-family. 

 Thus the genus Hexagona has subrotund or hexagonal and usually 

 large pores; the genus Parol us large, angular pores which are 

 elongated radially; the genus Baedalia typically labyrinthiform 

 pores. In the genus Lenzites the pores become changed so that 

 their poroid character is not always readily discernable. The 



