FLOWERING PLANTS OF NANTUCKET 437 
Missing thus certain plants not debarred by climatic condi- 
tions Nantucket has received into its flora other northern species 
even less to be expected there. There is some reason to believe 
that these plants may not have come to Nantucket directly from 
the north but from a more eastern part of their range. Just as 
Nantucket’s coastal plain flora partly reappears in the Maritime 
Provinces and even in Newfoundland, so, conversely, do many 
northward species characteristically associated in these regions find 
themselves together on Nantucket. Whether this association of 
their plants, many of which are of wide distribution, points back 
to some common heritage in the floras of these regions our present 
knowledge does not assure us. But something of affinity between 
these far separated floras seems to sketch itself in outline and not 
without features more clearly drawn. Such plants of Nantucket 
as Fragaria terrae-novae, Ribes oxyacanthoides var. calcicola and 
Antennaria petaloidea var. subcorymbosa would scarcely be 
looked for from elsewhere than far to the east. If an ancient 
land connection has conducted southern forms to these far 
eastern fields, some counter extension of northern forms, at least 
in the later age of that one time highway, may well have taken 
place. It is in point that almost directly to the north of 
Nantucket in eastern Massachusetts, at no greater distance than 
Essex County, nowhere of much elevation, many northern plants 
prevail that have obtained no foothold on Nantucket, even though, 
as we have seen, the island offers locally soils and conditions that 
are acceptable to northern woodland plants. And nearer at hand, 
in the Cape Cod region, where many of the conditions repeat 
those of Nantucket and many features of the flora are the same, 
there are, well in place, northern plants that have failed to cross 
the narrow strip of water to Nantucket. And, emphasizing in an 
unexpected way this slight rift of disconnection between the similar 
floras of these coastwise tracts, there are many southern plants 
of the Cape Cod region, not a few of them well established there, 
although at the extreme northern limit of their range, that on Nan- 
tucket are unknown.* 

* See, wom Gam S. Collins, Notes on the Flora of lower Cape Cod. Rhodora 
II: 125-133. 1909. Also, Flora of lower Cape Cod; supplementary note. Rhodora 
12:8-10. 1910. Also, Flora of lower Cape Cod; third note. Rhodora 13: 19-22. 
911. Also Sinnott, The pond flora of Cape Cod. Rhodora 14: 25-34. 1912. 
