396 PLANT DISEASES 



Merulius, Hall. Hymenium developing on a loose weft 

 of mycelium, surface variously plicate or wrinkled, the folds 

 forming irregular pores, and sometimes obsoletely toothed ; 

 spores colourless or coloured; substance often sub- 

 gelatinous. 



Merulius lacrymans, Fries, Syst. Myc., i. p. 328 (1821). 

 Broadly effused, usually entirely resupinate, but some- 

 times effuso-reflexed, thick, soft, and rather moist, silky or 

 velvety below, yellowish-brown in the centre, shading off 

 to the tumid, silky, white, or yellow margin; folds of 

 hymenium wavy, forming irregular pits ; spores rusty- 

 yellow, obliquely elliptical, 10-12 x 5-6 /x. 



Hydnaceae. Hymenium borne on acute spines, teeth, 

 warts, or irregular folds; basidia tetrasporous except in 

 Knieffia and Mucronella, where they are said to be mono- 

 sporous. 



Hydnum, Linn. Hymenium inferior or superior, borne 

 on pointed spines that remain perfectly free and distinct 

 from each other at the base. 



Hydnum schiedermayeri, HeufL, Oest. Zool. Bot. Zeitschr., 

 1870, p. 33. Fleshy, broadly effused, immarginate, 4-10 

 in. across, irregularly tuberculose, with tufts of pendulous, 

 subulate spines up to i in. long, often compressed, and 

 the tip more or less fimbriate ; flesh yellow, becoming 

 rufescent. 



Hydnum diversidens, Fries, Syst. Afyc., i. p. 411. 

 Pileus 2-3 in. across, fleshy and irregularly tuberculose or 

 lobed, sometimes substipitate, whitish or yellowish, upper 

 surface with erect, irregularly notched teeth ; the margin 

 clothed with club-shaped, sterile teeth ; under surface with 

 simple, awl-shaped, regular spines 3-6 lines long. 



