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CLASS BASIDIOMYCETEAE: SUBCLASS 

 EUBASIDIAE, "GASTEROMYCETEAE" 



Gasteromyceteae 



THE name Gasteromyceteae (often spelled Gastromyceteae) is given 

 to a group including those orders of Basidiomyceteae which have one- 

 celled, two- to four-spored basidia (rarely with more spores) produced 

 within closed spore fruits. These may have definite means of dehiscence 

 by which the spores reach the exterior or they may depend upon animals 

 which feed upon the spore fruits and thus carry the spores to various 

 places, or the spores escape only upon the decay of the spore fruits. 

 Mostly the basidia are produced in hymenia which line closed cavities, 

 but the latter instead of being exposed to the air at the time of spore 

 maturation, as in the Hymenomyceteae, remain closed until after the 

 spores have been produced. Frequently the spore fruits are produced 

 underground, emerging as they approach maturity or remaining sub- 

 terranean. Other forms grow on stumps, logs, etc. The mycelium usually 

 shows the presence of clamp connections. Conidia are known in a few 

 forms. Sexual reproduction is practically unknown, except for the union 

 of the two nuclei in the young basidium. Few species of this group have 

 been grown successfully in culture. Even the germination of the spores 

 has been found impossible of accomplishment in many species. The 

 basidia may be clavate or cylindrical, as in the majority of the Hymeno- 

 myceteae, but in the main are more inclined to be ovoid or globose with 

 sterigmata varying from short to long or even lacking. The spores are 

 perched symmetrically at the tips of the sterigmata and are not dis- 

 charged with violence as in the preceding orders. Sometimes the long 

 sterigma or a portion of it remains attached to the spore, like the handle 

 of a drumstick. 



The young basidia are binucleate and the two nuclei unite, this union 

 being followed by meiotic divisions leading to the production of four 

 haploid nuclei. The first meiotic spindle is transverse in the majority of 



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