CHAriER XVIII 



BASIDIA-BEARING FUNGI (SMUTS) 



ORDER BASIDIOMYCETALES 



The fungi of this order have mostly a strongly developed mycelium, 

 multicellular and at times with apical growth. Sexual reproduction is 

 entirely absent, yet in the rusts, we find certain nuclear fusions which 

 are looked upon by some mycologists as of a sexual nature. The 

 characteristic method of reproduction is non-sexual by means of conidia, 

 which in the most primitive forms are of indefinite number, 

 while in the most highly differentiated forms the conidiospores are 

 definite in number two to eight, and are borne on special conidio- 

 phores known as basidia (basidium-ia). In many forms, the basidia 

 are arranged in definite parts of fleshy fruit bodies and in special layers 

 known as hymenia (hymenium-ia). Besides the conidiospores other 

 kinds of spores, known as chlamydospores, are formed. Zoospores are 

 entirely absent. The fungi of the order are either saprophytes, or 

 parasites, and occasionally, they are facultative saprophytes, or faculta- 

 tive parasites. None of them live in the water (nicht wasserbewohnend) . 



The Basidiomycetales do not follow the Ascomycetales in the direct 

 line of evolution of the fungi. They may be considered to parallel the 

 sac fungi. The group is supposed, in this regard, to represent the results 

 of extreme simplification; the sexual organs, if ever present, have in 

 the phylogenetic history of these fungi long since disappeared and 

 simple nuclear fusions function in all probability in lieu of the sexual 

 act. 



Key to Suborders of the Basidiomycetales (After Stevens) 



Chlamydospores at maturity free in a sorus, produced intercalary, 

 from the mycelium; basidiospores borne on a promycelium and resem- 

 bling conidiospores. i. Hemibasidii. 



Chlamydospores absent, or when present, borne on definite stalks. 



Basidia septate, arising from a resting spore, or borne directly on a 

 hymenium. 2. Protobasidii. 



Basidia non-septate, borne on a hymenium. 3. Eubasidii. 

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