FUNGI: BASIDIUM FUNGI 299 



465. The hedgehog fungi, or tooth fungi (Hydnacea). The 

 members of this family are called " hedgehog " fungi, or " tooth " 

 fungi because they bristle with long spines which hang downward. 

 Some of the much branched forms are also popularly called coral 

 fungi. The fruiting surface covers the surface of the spines 

 which are often called teeth. 



466. Puffballs, earth stars, etc. These make up a large 

 group of fungi containing several orders. They grow on the 

 ground, or on rotting wood, and a few on the bark of living trees. 



Fig. 276. 



Earth stars (Geaster triplex), showing the outer layer of the Avail divided in a star-shaped 

 manner and recurved. The opening where the spores escape is in the conical apex of the 

 inner layer. 



A few are subterranean. They are mostly rounded or oval in 

 shape, and a few have short or long stems. In nearly all, the fruit 

 body has an envelope, the wall or peridium, which opens irregu- 

 larly in some, as in the giant puffball, or with a minute pore at 

 the apex. In the " earth stars '' the outer layer of the wall splits 

 regularly and turns back in the form of a star, while the inner layer 

 opens by a pore at the apex. The interior of most of the puffballs 

 is a many chambered structure, on the walls of which the fruiting 

 surface is formed. At maturity the internal tissue mostly breaks 

 down into a powdery mass which, with the spores, makes the 

 " smoke " of the puffballs. The " stink horn " fungi are related 



