POLY PO RALES 



441 



ally branched, spines of variable length (dendrophyses Fig. 285, 2). 

 Perhaps they are to be regarded as organs of protection. In addition, 

 gloecystidia have been found in some forms. 



In the higher genera, as in Cyphella (fructifications membranous), 

 Cytidia (Auricuiariopsis) (fructifications gelatinous), the fructifications 

 are raised from the central point of attachment by a compressed, short 

 stipe; they then assume an infundibuliform or cup shape, whose inner side 

 is corrugated and bears the hymenium. 



In Solenia, finally, the hyponastic growth begins very early and causes 

 elongate, cylindrical fructifications which are mostly joined gregariously 

 in membranous colonies. Their edges often bend together and enclose 

 the hymenium during drought. 



Fig. 285. — Aleurodiscus amorphus. 1. Section of hymenium with basidia and pseudo- 

 physes. 2. Aleurodiscus sparsus. Section of an apical portion of fructification with basi- 

 dia, dark gloeocystidia and denticulate dendrophyses. (X335; after Hoehncl and 

 Litschauer, 1907.) 



Clavariaceae. — While the stichobasidial line discussed in the Cantha- 

 rellales contains a few representatives of this family, the main group 

 of several hundred forms is probably predominantly chiastobasidial and 

 hence should be discussed under the Polyporales. The simpler genera, 

 Pistillaria (two-spored basidia) and Typhula (four-spored basidia), 

 develop clavate fructifications from sclerotia and are entirely covered 

 with a hymenium. In a few species of Typhula, the hymenium is 

 limited to the tops of the clubs. T. variabilis on dry stems and humus 

 and T. Betae, on decaying roots of sugar and other beets, winter over 

 with small sclerotia, each consisting of a light core and a dark rind 

 which is cutinized on the outside. The sclerotia germinate in spring 

 to a luxuriant mycelium whose hyphae, in T. variabilis, bear an immense 

 number of elongate oidia on short branches (Brefeld, 1887). The 

 hyphae intertwine to thick bundles which swell clavately and proceed 

 to form hymenia. Kuehner (1926) figures typical transverse spindles in 

 the basidial nucleus of Typhula Candida. In other genera, the fructifica- 



