356 BRITISH FUNGI 



join the flesh at different levels. Cap fleshy, semiorbicular, and 

 attached by a broad base, corky or woody. Several of the species 

 have a strong, spicy smell. 



D.EDALEA 



Cap corky or woody, sessile, and attached^by'[a broad base, or 

 entirely adnate to the substratum. Distinguished by the wavy, 

 often very much elongated pores, which sometimes almost resemble 

 gills. The walls or dissepiments of the tubes are often thick, 

 corky, and tough. 



Merulius 



Mostly forming a thin, subgelatinous layer entirely attached to 

 the substratum, in some species the margin is more or less free and 

 reflexed. Hymenium consisting of very shallow, irregular, wavy 

 pores. Merulius lacrymans, well known under the name of " dry 

 rot," is very destructive to worked timber. 



Boletus 



Usually large, very fleshy fungi. Cap very thick, convex, even ; 

 stem central, stout, hymenium on the under surface of the cap, 

 consisting of myriads of closely packed tubes, pores or open ends 

 of tubes, circular, angular, or wavy. Mass of tubes readily separable 

 from the flesh of the cap. 



Amongst the largest of our terrestrial fungi, the cap of B. edulis, 

 a typical species, has been aptly described as resembling in size, 

 shape, and colour a penny bun. In some kinds the white or yellow- 

 ish flesh instantl}' changes to a more or less intense blue colour 

 wlien broken and exposed to the air. Distinguished from the 

 fleshy forms of Polyporus by the mass of tubes readily separating 

 in a clean, unbroken manner from the flesh of the cap. Strohilo- 

 niyces is most closely related to Boletus, but is readily distinguished 

 by the coarsely scaly cap and globose spores. 



With one exception, all the species grow on the ground. Several 

 are edible. 



I. Surface of hymenium yellow, orange, greenish, or buff. 



* A ring present on the stem. 



B. luteus. — Cap 3-4 in. -across, thick, at first covered with a 

 brown, very viscid substance, becoming dry and paler, flesh 

 whitish, not changing colour ; tubes about -|- in. long, yellow ; stem 

 3-4 in. long, stout, yellow, rough with raised points abo^'■e the 

 large whitish ring. 



On the groimd in pine woods. 



B. elegans.- — -Cap 2-4 in. across, almost plane, clear yellow or 

 tawny golden, viscid, flesh not changing colour ; tubes about \ in 

 long, sulphur- yellow ; stem 3-4 in. long, yellow, minutely dotted 

 above the somewhat fugacious white ring. 



In woods, especially larch. 



