484 MINNESOTA BOTANICAL STUDIES. 



Twelve genera are recognized, nine of which are found in this 

 country. They may be distinguished by the following table: 



Ascoma clavate or subcapitate, continuous with the stipe. 

 Spores one-celled, colorless. 

 Light colored, usually yellowish or light brown; ascoma 



sharply separated from the stipe Mitrula.. 



Bright or dark colored; ascoma not clearly separated 



from the stipe Microglossum. 



Spores 2— many-celled by cross septae. 



Spores colorless Leptoglossum . 



Spores brown Geoglossum . 



Ascoma flat, decurrent on both sides of the stipe; 



spores rod-shaped Spathularia . 



Ascoma capitate or hollow-discoid usually with a free margin. 

 Spores ellipsoid. 



Gelatinous-gristly Leotia. 



Waxy Cudoniella . 



Spores elongate-filiform. 

 Fleshy; ascoma concave, hat-shaped, the margin 



free, incurved Cudonia. 



Waxy; ascoma discoid above, the margin adnate 

 to the stipe Vibrissea. 



Of the above genera we have one species in Vibrissea, two each 

 in Cudonia, Cudoniella, and Spathularia, five in Leotia and six 

 in Mitrula. The other genera are divided into well marked 

 sections. Geoglossum is represented by ten species arranged in 

 two sections: 



§ Eugeoglossum with smooth stipes, containing G. difforme, 

 nigritum, ophioglossoides, peckianum, and viscosum. 



§ Trichoglossum with hairy or bristly stipes, containing G. 

 americanum, farlowi, hirsutum and velutipes. G. farinaceum 

 has not been collected since its first discovery by Schweinitz 

 and its characters are, therefore, imperfectly known. 



Leptoglossum also contains two sections: 



§ Euleptoglossum, blackish, containing L. microsporum and 

 tremellosum. 



§ Xanthoglossum, yellowish or yellowish-brown, containing L. 

 luteum. 



Microglossum is likewise formed of two sections: 



§ Eumicroglossum, containing the dark colored (olive green) 

 species, M. viride, and 



§ Geomitrula, containing the bright colored (yellowish or 

 reddish) species: M. album, arenarium, elegans, lutescens, pis- 

 tillare, rufum and viteliinum. These were all united to Mitrula 

 by Saccardo. 



