240 HYDNEI. 



Hydnum. ** Simple, tuberculiform, immarginate. 



18. H. erinaceum Bull. — Pileus 20 cent. (8 in.) and more 

 broad, often much less, white, becoming yellow, fleshy, elastic- 

 tough, pendulous, tubercular, immarginate, torn into fibrils 

 above. Spines very long, 4-6 cent. (iX _2 X m -)> straight, equal, 

 pendulous. 



Striking, changeable in form, in the form of a heart when most perfect, 

 often with the rudiment of a lateral stem. Internally as if latticed in a 

 branched manner. 



On trunks of oak, beech, &c. Rare. 



Spores white, plain, 5x6 mk. W.G.S. Name — erinaceus, a hedgehog. 

 From its appearance. Bull. t. 34. Fr. Hym. Eur. p. 608. Berk. Out. p. 

 259. C. Hbk. 71. 852. Vittad. t. 26. Krombh. t. 51./. 1-3. 



19. H. caput-Medusae Bull. — White, then fuliginous-cinereous, 

 fleshy, tuberculiform, somewhat stipitate. Spines on upper 

 surface distorted, the lower ones long, straight. 



Large. The trunk is dilated into a pileus, which is covered over with 

 slender spines on all sides. 



On trunks. Rare. 



Name — Medusa's head. Bull. t. 412. Fr. Hym. Eur. p. 608. Berk. 

 Out. p. 259. C. Hbk. u. 853. 



IV. — Apus. Pileus sessile, dimidiate, &c. 

 * Pileus fleshy, soft. 



20. H. cirrhatum Pers. — Pileus pallid, fleshy, expanded, 

 fibrilloso-curled above with scattered decumbent abortive spines, 

 the fimbriate margin incurved. Spines very long, 10-16 mm. 

 (5-8 lin.), slightly tough, equal. 



Simple or imbricated. Varying white, light yellowish, rufescent. 



On a beech-tree. Epping Forest. 



Name — cirrus, a curl, lock of hair. Pileus curled. Pers. Syn. p. 558. Fr. 

 Hym. Eur. p. 609. Sv. all. Sv. t. 71./. 1. B. & Br. n. 1370. Fl. Dan. t. 

 1789./. 2. 



21. H. diversidens Fr. — Pileus 5 cent. (2 in.) broad, white 

 fleshy, thick, substipitate, very irregularly shaped, densely beset 

 above with erect, variously shaped, incised teeth, clothed at the 

 entire margin with club-shaped spines, and beneath with entire 

 awl- shaped regular spines. 



Colour almost that of repandum. Singular from having spines of three 

 kinds. Allied to H. cirrhatum, but not caespitose, more irregularly shaped, 

 here and there lobed. 



