530 



COMPARATIVE MORPHOLOGY OF FUNGI 



DACRYOMYCETALES 



CANTHARELLALES 



DACRYOMYCETACEAE 



Dacrvomyees Caloeera 

 GuepiniaN 



Dacrvomyees 

 Ceracea 



X 



CANTHARELLACEAE 



Hydnum Cantharellus Thelephora 

 Craterellus 



CLAVULINACEAE 



Clavulina 



t 

 EXOBASIDIACEAE 



Exobasiclium 

 Kordyana 

 Peniophora eorticalis 



Ascocorticium group - 



Diagram XXXII. 



Exobasidiaceae. — This family, usually included in the Corticiaceae 

 by systematists (e.g., Burt, 1915), contains primitive, resupinate species. 

 The only saprophytic species, Peniophora eorticalis (P. quercina, Kneif- 

 fia eorticalis), forms resupinate crusts on twigs. The hyphal cells are 

 originally binucleate but later, by nuclear division without septation, 

 they become multinucleate (Maire, 1902) . Clamp connections are abund- 

 ant. The smooth hymenium consists of four-spored basidia and cystidia 

 which are sunk deep, so that only the tips project beyond the basidia. All 

 the other species of this genus which have been investigated belong to the 

 chiastobasidial type. The germination of the basidiospores is unknown. 



Kordyana is parasitic on leaves of tropical species of Commelinaceae, 

 causing brown spots, surrounded by a light green zone. The hemispher- 

 ical hymenia, white or yellowish, are erumpent from a hyphal tissue in the 

 substomatal air passage on the underside of the spots (Fig. 351). They 

 consist of basidia and sterile hyphae (paraphyses) exceptionally of basidia 

 only. The basidia are rather variable in form. At maturity they gener- 

 ally contain four nuclei; usually producing two spores. In damp nights, 

 there may be formed successively, small fascicles of as many as six spores 

 in which mature and immature spores are intermingled. They germinate 

 either by germ tubes or by sprout mycelia (Gaumann, 1922). 



Exobasidium biologically bears a relationship to Kordyana, similar 

 to that of Albugo and Peronospora to the Pythieae in the Oomycetes. 

 The hyphae of Kordyana penetrate the infected tissue in all directions 

 and kill it; those of Exobasidium have adapted themselves to the host 

 and stimulate it to form galls and witches' brooms, rather than kill it. 

 In this respect, Exobasidium resembles Taphrina in the Ascomycetes. 



Exobasidium Vaccinii, parasitic on many Ericaceae, especially on 

 Vaccinium Vitis-Idaea (Fig. 352), has been studied in great detail 

 (Woronin, 1867; Brefeld, 1889; Maire, 1902; Burt, 1915; Eftimiu and 



