1921] Third Report on Floral Areas 213 



Marsilea quadrifolia was first reported in the addenda to the fourth 

 edition of Gray's Manual in 1863 from Bantam Lake, Litchfield, 

 Conn., where it had heen collected by Dr. T. F. Allen, and was long 

 supposed to be native there. It does not appear, however, in J. P. 

 Brace's comprehensive list of plants of Litchfield and vicinity pub- 

 lished in 1822: very probably, as is surmised in the 7th edition of 

 the Manual, it was "casually introduced" at some time between 

 these two dates. Another Connecticut station, at Cromwell, is 

 known to have existed for at least 45 years. The plant is easily 

 established in still, shallow water and has been introduced at Maran- 

 acook and Skowhegan, Maine; Boxford, Billerica, Concord, Salem, 

 Maiden, Cambridge, Jamaica Plain, West Roxbury, Needham and 

 Dedham in eastern Massachusetts; and, besides the two stations 

 above mentioned, at New Haven and Middlebury, Conn. 



The arrangement of the native species given below follows in gen- 

 eral that of our last report: readers are referred to that report for 

 definitions and explanation of groups there adopted. We have 

 recognized here four new groups, for the reasons given under them 

 and from the belief that better results can be obtained by creating 

 categories as numerous as may be required to bring like ranges to- 

 gether than by attempting to crowd all our plants, almost endlessly 

 various in their distribution as they are, into a few generalized di- 

 visions. Where possible, we have used, as titles for the groups, 

 condensed statements of the ranges concerned and in so doing have 

 employed more definitely than hitherto the Cape Cod region'' and 

 the upper St. John valley in northern Aroostook Co., Maine, 8 as, in 

 some sort, index areas. These two regions— the former mainly of 

 sandy, acid soils without rock outcrops and of oak and pitch pine 

 barrens, the latter with heavy, often calcareous soils, river cliffs and 

 wide stretches of Canadian forest; one with the mildest climate in 

 New England, the other with one of the most severe — are well-nigh 

 complete antitheses of each other. One offers the extreme of austral 

 conditions, the other, (except for the very limited alpine areas on 



f ' Comprising .southeastern Plymouth County and all of Barnstable, Dukes, and 

 Nantucket Counties. This region is not homogeneous, as the oreurrenee in eertain 

 Localities within it of such woodland types as llotruchium ramosum and Lycopodtum 

 luridulum testifies; but these boundaries seem sufficiently accurate for our present 

 purpose. The region is referred to, for brevity, as Cape Cod. 



6 Comprising that part of Aroostook County north and west of the Aroostook 

 Valley. Referred to as the upper St. John. 



