HARPER: VEGETATION OF THE HEMPSTEAD PLAINS 279 
tenuifolia, which may be native in some parts of the eastern 
United States, but nearly always grows in places whose natural- 
ness is not above suspicion, all the way from here to Florida. 
Agrostis alba is very common also along roads, and most of the 
other species whose names are in parentheses in the upland 
vegetation list grow in similar places, where the original vegeta- 
tion has been damaged without much disturbance of the soil. 
None of them seem to invade undisturbed vegetation, however. 
Where the soil has once been plowed up and cultivated many 
additional weeds, such as Oenothera biennis, Ambrosia artemisii- 
folia, Persicaria sp., Linaria vulgaris, Daucus Carota, Syntherisma 
sanguinalis, and Aster ericoides, come in, and these seem able to 
hold the ground indefinitely against a re- invasion by native 
species. Very little attention has been paid to this particular 
phenomenon as yet, but there will be time enough for it after the 
natural vegetation, which needs more immediate attention, is all 
gone. 
COMPARISONS WITH OTHER REGIONS 
There is no precisely similar vegetation anywhere else, as far 
as known, but there are many places near and remote with vegeta- 
tion somewhat similar in aspect or composition, or both. Among 
the nearer places are the so-called heaths of Nantucket, described 
by Harshberger,* and Block Island, Montauk Point, and various 
other places near the coast of southern New England, if we may 
judge by the few photographs and fragmentary floristic descrip- 
tions that have been published, though in some of these cases the 
treelessness is said to be the result of deforestation within historic 
times, 
The “hilltop barren. formation" of eastern Massachusetts, 
described by Blankinship,] has quite a number of species in 
common with the area under consideration. In the government 
soil survey of Rhode Island by F. E. ‘Bonsteel and E. P. Carr, 
published in 1905, there is described a "Miami silt loam,"1 
occurring principally in the township of South Kingstown, in the 
* Bull. Geog. Soc. Phila. 12: 73-76. 1914. 
1 Rhodora 5: 12 дА, May, 1 
: + In a subsequent publication oi the Bureau of Soils this was changed to “ 27” 
mac silt loam,” a type of soil not reported outside of Rhode Island, and classed as 
glacial lake deposit 
