SECT. I 



CRYPTOGAMS 



411 



Fli^. 345. — Clararia botryiis. (Xat. size.) 



centric zones. In consequence of tlii.s mode of growtli, where the development 

 lias been undisturbed, the fructitication.s, which appear in autumn, form the so- 

 called fairy rings. A few Hj^menomycetes are parasitic, and vegetate in the bark 

 or wood of trees. 



The Hymenomycetes arc further classified according to the increasing complexity 

 exhibited in the structure of 

 tlieir basidial fructitications. 



1. In the Exobasidiineae 

 no distinctive fructifications are 

 formed, and the basidia spring 

 in irregular groups directly from 

 the mycelium. Exohasidium 

 Vaccina may be taken as a type 

 of this form. The mycelium of 

 this fungus, which is widely 

 spread in Europe, is parasitic ill 

 the Ericaceae, especially on 

 species of Vaccinium ; it causes 

 hypertropliy of the infected parts. 

 The basidia are formed in groups 

 under the epidermis, M'hich they 

 finally rupture (Fig. 344). In 

 this genus, as in many others, 

 accessory fructifications are developed, and spindle-shaped conidia are abstricted 

 from the myeeliuni on the surface of the host plant, before the formation of 

 the basidia. 



2. In the group of the Thelephoreae, distinctive fructifications of a simple type 

 are found. Tliey form on the trunks of trees either flat, leathery incrustations 

 bearing tlie liymenium on their smootli upper surfaces ; or the flat fructifications 



become raised above the substratum and 

 form bracket-like projections, which fre- 

 quently show an imbricated arrangement, 

 and bear the liymenium on the under 

 side {e.g. Stcreum Mrsutwin, common on 

 the stems of deciduous trees). 



3. The fructifications of tlie Clavarieae 

 form erect whitish or yellow - coloured 

 bodies, either fleshy and club-shaped or 

 more or less branched, in a coral -like 

 fashion. The larger, profusely branched 

 forms of this group are highlj' esteemed 

 for their edible qualities ; in particular, 

 Clavaria flava, whose fleshy, yellow- 

 coloured fructifications are often ten centi- 

 metres high, also Clavaria botrytis (Fig. 

 345), which has a pale red colour. 



Sparassis crisiui, which grows in sandy soil in Pine woods, has fructifications lialf 



a metre in diameter, with compressed, leaf-like branches. 



4. The Hydneae have fructifications with s})inous projections over wliicli the 



liymenium extends. In the simpler forms the fructifications have the ajipearance 



of incrustations, with spinous outgrowths projecting from tlie upper surface ; in 



Fig. 346. — Jliidnnm repandum. fReduced.) 



