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, Sysf. Myc, i. p. 328 (182 1). 

 — 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 /i. 



Hydnaceae. — Hymenium borne on acute spines, teeth, 

 warts, or irregular folds ; basidia tetrasporous except in 

 Knieffia and Miicronella, 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. Myc, 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. 



