MIDDLESEX FLORA. 171 



P. communis, DC. 



Natick. 

 P. pustulata, (Ach.) Nyl. 

 Sherborn. 



CONOTREMA, Tuck. 



C. urceolatum, (Ach.) Tuck. 

 Cambridge, VYaltham, Natick, Sherborn. 



Urceolaria, (Ach.) Flot. 



U. scruposa, (L.) Nyl. 

 Chelmsford, Cambridge, Watertown. 



Myriangium, Mont. & Berk. 



M. Duriaei, (Mont. & Berk.) Tuck. 

 Newton (C. J. Sprague). 



Stereocaulon, Schreb. 



S. paschale, (L.) Fr. 



Medford, Waltham. 



Cladonia, Hoffm. 



C. alcicornis, (Lightf.) Floerk. 



Cambridge, Watertown. 

 C. cariosa, (Ach.) Spreug, 



Cambridge. 

 C. pyxidata, (L.) Fr. 



Cambridge, Waltham, Natick, Sherborn. 

 C. gracilis, (L.) Nyl. 



Waltham. 

 C. gracilis, (L.) Nyl., var. verticillata, Fr. 



Natick, Waltham. 

 C. gracilis, (L.) Nyl., var. hybrida, Schaer. 



Natick. 

 C. cornuta, (L.) Fr. 



Sherborn. 

 C. cenotea, (Ach.) Schaer. 



Waltham. 

 C. caespiticia, (Pers.) Fl. 



Waltham. 

 C. furcata, (Huds.) Fr. 



Waltham. 

 C. furcata, (Huds.) Fr., var. racemosa, Fl. 



Waltham, Sherborn. 



