90 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 



purple though sometimes becoming yellowish; those of var. sabulo- 

 nensis at first purple, but in maturity, becoming yellow like those of 

 the more southern species. On Newfoundland and Cape Breton 

 B. iodandra is in flower through August, but the Sable Island plant 

 is some weeks later, the material collected August 30, being only in 

 bud. 



Combining the color, foliage, and most of the flower-characters 

 of B. wdandra with the habit and more deeply cleft calyx of B. 

 paniculata, the Sable Island plant presents an interesting transition. 

 B. paniculata is characteristic of the Coastal Plain from Louisiana 

 to southeastern Massachusetts, rarely extending to southernmost 

 Maine. B. iodandra in typical development is confined to Cape 

 Breton and Newfoundland; and the transitional plant to the isolated 

 Sable Island, one of the last remnants of the ancient continental 

 shelf which extended from southern New England to the Newfound- 

 land banks. It would thus seem probable that the widely distrib- 

 uted southern B. paniculata originally spread northward on the 

 continental shelf, becoming modified toward the North, the Sable 

 Island plant still retaining some distinctive paracw/ata-characters, 

 which have disappeared from the more northern and further isolated 

 B. iodandra of Cape Breton and Newfoundland. 



Menyanthes trifoliata L. "Quite rare, in ponds at No. 3 sta- 

 tion." Found only by J. Macoun (C. no. 22,541). 



Centaurium umbellatum Gilib. Very common in the wet 

 dune hollows, and by the wet sandy borders of the fresh-water ponds. 

 Not near the Life Saving Stations or the Lighthouses and not giving 

 any indication of being introduced. This species has been known 

 in North America for a long time, but it has universally been treated 

 in botanical manuals as an introduced plant. This seems to be 

 the true explanation in the greater number of the cases, such as the 

 record from Concord, Massachusetts, 1 A. W. Hosmer reporting it "found 

 at Concord in 1890, not seen since." The species is occasional 

 in the State of Michigan, but there it also seems to be an introduction. 



There is, however, a station near Oswego, New York, which has 

 been known for nearly a hundred years. In 1833 Beck reported, 2 



*As Erythraea Centaurium Pers., Rhodora i. 224 (1899). 

 2 As Erythraea Centaurium Pers., Beck, L. C.: Bot. of N. and Middle States, 

 242 (1833). 



