152 



PLANT MORPHOLOGY 



2. Sclerodermaceae. In this family the basidiocarp is nearly spherical, 

 with a thick, leathery, one-layered peridium that ruptures at the apex. 

 The gleba is indistinctly chambered. The basidia are borne on lateral 

 branches of the glebal hyphae. There are no sterigmata, the basidio- 



spores being sessile. The representa- 

 tive genus is Scleroderma. 



3. Lycoperdaceae. These are the 

 familiar puffballs. The globular basid- 

 iocarps are usually less than 8 cm. in 

 diameter but sometimes reach 50 cm. 

 or more. The peridium is two-layered 

 and has no definite dehiscence. In 

 Lycoperdon the outer layer flakes off, the 

 inner one bursting at the apex to liber- 

 ate the spores. In Geaster the outer 

 layer splits into stellate segments that 

 spread out on the ground, the inner 

 one dehiscing by a terminal pore. In 

 this family the gleba is distinctly cham- 

 bered. It is lined with a hymenium 

 and contains a capillitium consisting of 

 fibrous interwoven hyphae that aid in 

 spore dispersal. 



4. Nididariaceae. The bird's-nest 

 fungi resemble the puffballs in their 

 younger stages, but at maturity the 

 peridium opens and becomes cup- 

 shaped. The separate glebal chambers, 

 with much-thickened walls, lie at the 

 bottom of the cup like eggs in a nest. 

 The two chief genera are Nidularia and 

 Cyathus. 



5. Phallaceae. The stinkhorn fungi 

 are the highest of the Basidiomy- 



cetes. Their basidiocarps are extremely complex (Fig. 124). At first 

 they are white and egg-shaped. The peridium is two-layered but the 

 tissue within is differentiated into a hollow sterile axis and an investing, 

 dome-like, chambered gleba. When the basidiocarp is mature, these 

 become the stipe and pileus, respectively. The gleba becomes mucilagi- 

 nous and foul-smelling, attracting carrion flies that distribute the spores. 

 The principal genera are Phallus, Mutinus, and Dictyophora. In Dicty- 

 ophora there is a conspicuous net-like veil that hangs down beneath the 

 pileus and spreads out around the stipe like a skirt. 



Fig. 124. A stinkhorn fungus, P/iaiius 

 impudicus, natural size. 



