286 



COLLEGE BOTANY 



The Autobasidiomycetes are the true Basidiomycetes and arc- 

 known as the fleshy fungi. Some of the most important families 

 are the Agaricacece, the Hydn&ceace, the Polyporacea? and the 

 Lycoperdacece. The first of these families may be illustrated by 

 almost any common mushroom of the genus Agaricus. 



The Agaricacece (Fig. 136) or common mushrooms and toad- 

 stools are well known. The most common type has a stipe or 



FIG. 136. Two specimens of mushrooms. The one on the left shows the annulus or ring. 



stem and a pileus or cap bearing the lamella or gills. They arise 

 from a button which is produced from a mycelial growth that 

 may have been in existence for a long time. The button persists. 

 in many species as a volva or cup. When in the button stage the 

 edge of the pileus it attached to the stipe by a membrane known 

 as the velum. If it clings to the stipe it is known, as the annulus 

 or ring. The basidia are borne on the surface of the gills and 

 usually bear four spores each. 



