RADULUM. 



GENUS XXXVII. Radulum (from the root-like appearance of 

 the processes of the hymenium). Fr. Elench. p. 148. 



Hymenium amphigenous, tubercular. Tubercles rude, irregu- 

 larly shaped, commonly elongate, obtuse, waxy (except in. R. 

 aterrimuni], irregularly arranged, 

 distinct. Sporophores 4-spored, oc- 

 curring not only on the tubercles, 

 but also on the even parts of the 

 hymenium. Growing on wood, resu- 

 pinato-effused, often bursting through 

 the bark. Fr. Hym. Eur. p. 622. 



* Denuded, very variable. 

 ** Innate, removing the bark. 



* Denuded^ very variable. 



1. R. orbiculare Fr. A. First 



season's growth, white then yellowish, 

 orbicular, confluent, circiiniference 



flaxy. Tubercles elongated, some- 



what round, scattered or fasciculate. 

 B. Second season's growth, vernal, 



flesh-colour, waxy-fleshy, smooth. Tubercles softer, shorter, as 

 if rubbed away. 



Entirely changeable in form, but very distinct. The tubercles vary 

 flexuous. 



On dead bark, birch, cherry, &c. Frequent. Oct. 



5-7.5 cent. (2-3 in. ) broad, quite membranaceous or above 4 mm. (alin.) 

 thick. M.J.B. Name orbiculus, a small disc. Orbicular, round. Fr. 

 Hym. Eur. p. 623. Berk. Out. p. 263. C. Hbk. n. 874. S. Mycol. Scot. 

 n. 826. Grev. t. 278. 



. Radulum quercinum. 



Natural size. 



2. R. quercinum Fr. White then pallid, 5-7.5 cent. (2-3 in.), 

 somewhat round then broadly confluent, innate, crustaceous, 

 becoming smooth. Tubercles round, stout, obtuse, scattered or 

 fasciculate, irregularly shaped, floccoso-villous at the apex. 



Rude, changeable in form, often confounded with Hydnum squalinum and 

 H. variecolor. 



On dead oak. Rare. Dec. 



Name quercus, oak. Growing on oak. Fr. Hym. Eur. p. 623. Syst. 

 Myc. i. p. 423. Berk. Out. p. 263. C. Hbk. n. 875. S. Mycol. Scot. n. 827. 

 KaySyn. t. x./. 4. 



