THE FUNGI WHICH CAUSE PLANT DISEASE 131 



fertile portion more or less cap-like; hymenium free from the first 

 or covered with a thin, evanescent veil; " asci cylindric, opening 

 by an apical pore; spores ellipsoid, colorless or light yellow, smooth, 

 or in one genus echinulate. 



Key to Families of Helvellales 

 Ascocarp stalked 



Fertile portion clavate or capitate; asci 



opening by an irregular slit 1. Geoglossacete, p. 131. 



Fertile portion pileate ; asci opening by a lid . 2. Helvellacea. 

 Ascocarp sessile 3. Rhizinaceae, p. 132. 



The majority of the species of this order are saprophytes, the 

 only parasites being of the first and third families. Of the second 

 family many of the species are edible and some are very large. 



Geoglossaceae 



Key to Tribes and Genera of Geoglossaces 



Ascoma clavate or spatulate, ascigerous 

 portion usually more or less com- 

 pressed, rarely subglobose . . . . Tribe I. Geoglossese. 

 Ascoma clavate, fertile portion at most 

 only slightly decurrent 

 Spores small, elliptic, cylindric or 

 fusiform, continuous ; plants 



bright colored 1. Mitrula, p. 132. 



Spores long, elliptic to cylindric, 3 to 

 many-septate at maturity 



Hymenium bright colored 2. Microglossum. 



Hymenium black or blackish 



Spores hyaline 3. Corynetes. 



Spores brown 4. Geoglossum. 



Ascoma spatulate or fan-shaped, as- 

 cigerous portion decurrent on the stipe 

 Ascigerous only on one side of the 



stem 5- Hemiglossum. 



Ascigerous on both sides the stem 



Spores globose 6. Neolecta. 



Spores elongate 7. Spathularia. 



Ascoma stalked, capitate or pileate, in one 

 genus sessile H. Cudoniese. 



