168 MIDDLESEX FLORA. 



Physcia, (DC, Fr.) Th. Fr. 



P. speciosa, (Wulf., Ach.) Nyl. 



Watertown, Medford, Cambridge and Waltham (Tuckerman). 

 P. hypoleuca, (Muhl.) Tuck. 



Natick. 

 P. comosa, (Eschw.) Nyl. 



Cambridge, very rare (Tuckerman). 

 P. aquila, (Ach.) Nyl., var. detonsa, Tuck. 



Natick. 

 P. pulverulenta, (Schreb.) Nyl. 



Cambridge, AValtham. 

 P. stellaris, (L.) 



Natick, Sherborn. 

 P. stellaris, (L.), var, aipola, Nyl. 



Cambridge, Waltham. 

 P. tribacia, (Ach.) Tuck. 



Waltham, Sherborn. 

 P. hispida, (Schreb., Fr.) Tuck. 



Cambridge, Waltham. 

 P. obscura, (Ehrh.) Nyl. 



Waltham, Sherborn, Natick. 

 P. setosa, (Ach.) Nyl. 



Natick. 



Ptxine, Fr., Tuck. 

 P. sorediata, Fr. 



Waltham. 



Umbilicaria, Hoftra. 



U. Muhlenbergii, (Ach.) Tuck. 



Waltham (C. J. Sprague) ; Cambridge, Medford. 

 U. Dillenii, Tuck. 



Waltham. 

 U. pustulata, (L.) Hoftm., var. papulosa, Tuck. 



Waltham, Natick. 



Sticta, (Schreb.) Fr. 



S. amplissima, (Scop.) Mass. 



Waltham, Natick. 

 S. pulmonaria, (L.) Ach. 



Arlington, Waftham, Natick. 

 S. fuliginosa, (Dicks.) Ach. 



Waltham (Russell). 

 S. crocata, (L.) Ach. 



Waltham, Sherborn. 



