IV] 



HELVELLALES 



Geoglossaceae 



The Geoglossaceae grow usually in damp or moist situations such as 

 low, wet woods and shady slopes. They occur on soil or on dead branches 

 or leaves, and two species of Mitrula are parasitic on living moss. The 

 family includes some eight genera of which five are British. 



Fig. 91. a. Geoglossnm hirsnluin Pers., nat. size; b. Spathularia clavata Sacc., 

 nat. size; c. Leotia lubrica Pers., form stipitata, xf ; after Massee. 



The ascophore is erect and stipitate with the fertile portion terminal, 

 and either club-shaped (fig. 91 a, b\ laterally compressed, or forming a cup 

 or a pileus (fig. 91 c.}. In some of the simpler forms, as in Geoglossum 

 hirsutum, there is no clear line 

 of demarcation between the fertile 

 and sterile regions. The ascus con- 

 tains eight spores and opens by the 

 ejection of a plug. 



The young ascocarp consists of a 

 dense tangle of vegetative filaments ; 

 in the early stages a more or less 

 conspicuous veil has been identified 

 in several genera (though not as yet 

 in Geoglossum}. It is composed, as 

 in the Helvellaceae, of interwoven 

 hyphae, derived from and continuous 

 with the outer layer of the fruit body. 

 There are indications that it opens 

 at first by a pore at the apex, but it 



soon breaks up into scales and dis- 



Fig. 

 appears. s t 



i. Geoglossum hirsutum Pers., x 230; b. 



02. 

 Spathularia davata Sacc., x 400; after Massee. 



92 



