552 CLASS BASIDIOMYCETEAE 



160,000,000,000,000 spores. As in some of the Hymenogastrales the basal 

 portion of the spore fruit may remain sterile, not forming basidia in the 

 cavities which are produced in the sterile base. This is particularly charac- 

 teristic of the genus Lycoperdon in which the sterile base may be narrower 

 and resemble somewhat a broad stipe. In Calvatia the basal portion is 

 sterile in some species but not so markedly narrowed. The spore fruits of 

 all the species of this family appear to be edible when young, while still 

 white and rather brittle. The genus Lycoperdon has many species vary- 

 ing in size from 1 cm. to 5 cm. or more. The spore fruits are more or less 

 pear-shaped with a large sterile base. The exoperidium scales off as granules 

 or scales. The endoperidium has a single apical ostiole. They grow scattered 

 or in closely crowded masses on the ground or on decaying wood. (Fig. 

 182.) Calvatia differs externally from the preceding in the less pronounced 

 narrowing of the sterile base and in the absence of an ostiole in the endo- 

 peridium. The latter breaks off in large pieces. The capiUitium consists of 

 long, tangled, somewhat branched threads which usually break up into 

 short pieces at maturity. C. gigantea, occurring in the Fall in fields and 

 pastures, is collected for food while still firm and white. Bovista has a thin 

 exoperidium which sloughs off and a slightly thicker endoperidium with an 

 apical ostiole. There is no sterile base, the gleba filling the whole spore 

 fruit. The branched capillitial hyphae are slender and smooth and usually 

 not breaking into pieces. The sterigmata break loose from the basidium 

 and remain attached to the basidiospores. B. plumhea Pers. is 3 to 5 cm. in 

 diameter, nearly round and with a lead-gray endoperidium. Mycenastrum 

 has a rather thick endoperidium which cracks open in a more or less stel- 

 late manner. The capiUitium is composed of thick, branched, spiny 

 hyphae, tapering from the middle to the acute tips. The sterigmata are 

 very short so that the spores are almost sessile. Disciseda (Catastoma) has 

 a firm exoperidium which splits equatorially. The endoperidium pulls free 

 from the basal half of the exoperidium while remaining attached to the 

 upper half. The result is that the spore fruit escapes and blows around, 

 leaving the basal portion of the exoperidium still attached to the ground. 

 The ostiole pierces the endoperidium at the center of the exposed portion, 

 which is morphologically its base. Disciseda Candida (Schw.) Lloyd (C. 

 circumscissum) is common in grassy places in the prairie regions of the 

 United States and in similar regions in Eastern Europe. (Fig. 183.) Lan- 

 opiUi has a very thin peridium which separates in irregular pieces from the 

 gleba. This consists at maturity of a capiUitium of much entangled, 

 slender hyphae with the intermingled spores. The generic name was given 

 because of its resemblance to a ball of wool. Swoboda (1937) studied the 

 structure of the not quite mature spore fruits of L. bicolor (Lev.) Pat. and 

 found that the spores are borne on one side of the basidium on short 



