224 Rhodora [November 



POTAMOGETON' SPATHAEFORMIS A PROBABLE IIyBUID IN MySTIC 



Pf)j^p — The very local plant which was discovered in 1850 by the 

 late Edward Tuckennan in Mystic Pond, Medford, Massachusetts, 

 and called by him Potamogeton spathaejormis has never been found 

 elsewhere in America, and is not known to fruit. In Cambridijeshire, 

 England, however, h is known to Mr. Alfred Fryer to fruit, although 

 not abundantly, and Mr. PVyer has maintained that it is a hybrid 

 between P. hfterophi/llns and P. angusti]oUus . The late Dr. Thomas 

 Morong, while admitting the possibility that Mr. Fryer's interjjreta- 

 tion is correct, said: " but a weighty argument against this view is 

 the fact that neither of the supposed parents occurs in Mystic Pond, 

 and that it should be produced in localities separated by the Atlantic 

 ocean." ^ In view of Dr. Morong's positive statement, therefore, it is 

 important to record the fact that in the Gray Herbarium there is a 

 sheet of very characteristic P. angu.tf if alius collected by the late \\ m. 

 Boott in " Mystic Pond, August 26," (presumably in the GO's) ; and 

 that in both the Gray Herbarium and the herbarium of the New 

 England Botanical Club there are characteristic specimens of 7'. 

 Jwterophyllus collected in Mystic Pond by Messrs. E. & C. E. Faxon. 

 There is, then, no reason, as maintained by Dr. Morong, wliy P. 

 spathaejormis should not have originated by the hybridizing of P. 

 angustijolius and P. heterophyllus in Mystic Pond as well as in Cam- 

 bridgeshire, England.— M. L. FEHXAi.n, Gray Herbarium. 



'Morong, Mfiii. Torr. C'l. iii. no. 2, 27 (1893). 

 Vol. 8, 710. 94, including pages 189 to 204, ivas issued 25 October, 19()6. 



