274 POLYPOREAE OF SOUTH AFRICA. 



The fungus can be recognised by the context tissue between 

 the pore strata and the glistening of the mouths of the tubes. 

 Often the tubes are more yellowish than the context tissue and the 

 strata then show up especially well. 



2. Fames hornodermus (Mont) Cke. 



Pileus hard, woody, pereunial, sessile, dimidiate, plane above 

 and convex below or ungulate 4 cm. by 7 cm. by 11 cm.; surface 

 smooth, sulcate, dark-brown to black, horny encrusted and becom- 

 ing rimose with age; context white becoming pale-umber, woody, 

 1 mm. to 4 mm. thick but often exceedingly scanty; tubes 4 mm. 

 to 9 mm. long each season, white; mouths minute, subrotund, 

 3 to 4 to the mm. ; edges entire, white to yellowish; spores hyaline, 

 ovoid, 3-7/a to 6-4/a by 7/a to 9-2ju,; hyphae 4jm to 5-5/x. 



Distribution. — On undetermined host from Eshowe, Zululand, 

 by G. W. Hyslop; on Ocotea bullata in Lusikisiki Forest, Pondo- 

 land (Herb. Div. Bot. , Pretoria, No. 6936); from Rhodesia by C. 

 Swynnerton. 



The hard, horny encrusted surface combined with the hard 

 white tubes and woody context serves to distinguish this fungus 

 from others which may resemble it externally. 



3. Fomes geotropus, Cke. 



Pileus, large, hard and woody, up to 10 cm. thick, conchate; 

 surface rough, concentrically sulcate, white to cream coloured; 

 context corky to wood)'', white in fresh material changing to yel- 

 lowish in herbarium specimens, 4 cm. thick; tubes 0-2 cm. to 

 1-5 cm. long each season, stratified (in one South African specimen 

 the strata of successive years were separated from each other by 

 context tissue), dull brick-red fading in older layers; mouths 

 minute, subrotund 4 to 5 to the mm. : edges entire, bright coloured 

 when fresh; spores hyaline, globose, thick walled, 7/x diam; hyphae 

 3-7^. 



Distribution. — Recorded from Umtata, Pondoland, on live 

 Podocarpus sp. ; and by J. D. Keet from Knysna, on live Ocotea 

 bullata; from Rhodesia by C. Swynnerton. 



Recognised by the contrast in colour of context and tubes. 

 The existence of layers of context tissue separating the pore-strata 

 of successive years is not reported from elsewhere for this fungus 

 and is probably merely a growth condition. 



4. Fomes melanoporus (Mont) Cke. 



The specimens of this plant found in Africa by the writer 

 have all been resupinate and formed masses 9 cm. to 12 cm. or 

 more across and 01 cm. to 1 cm. thick, with thin rounded or acute 

 velvety margins; context purple to brown to dark reddish violet, 

 shiny, fibrous, becoming very hard and horny, 2 mm. or more 

 thick; tubes distinctly stratified, 2 mm. to 3 mm. long each season, 

 purple-brown fading to lighter; mouths subrotund to angular 5 

 to 6 to the mm.; edges entire, reddish violet to smoky black, 



