1912] Wiegand,— Notes on Amelanchier 241 
Anemone cylindrica, Parnassia caroliniana, Ribes, americanum Po- 
tentilla fruticosa, Sanguisorba canadensis, and Eupatorium. urticae- 
folium. It may, therefore, be inferred that limey soil exists locally 
in Groton and vicinity. 
The observations of another summer have served to strengthen the 
writer’s belief that crosses between species of Amelanchier frequently 
propagate themselves by seed, and become, therefore, definite local 
races. For example, in a brief visit to Woods Hole during the past 
summer, all the individuals of Amelanchier noticed were approxi- 
mately alike, but combined characters of both A. leavis and A. oblongi- 
folia. If one such specimen only had been found, it would have been 
ascribed unquestionably to a hybrid origin, but to find so many was 
` perplexing. During the visit to Woods Hole, no specimens of typical 
A. laevis or of A. oblongifolia were seen, a fact which seemed to render 
a hybrid origin of this form very improbable. It must be remembered, 
however, that in so brief a visit, in midsummer, occasional typical 
specimens of these two species might have been easily overlooked; 
and that herbarium specimens show the existence of both species in 
the general region about Woods Hole. It must also be remembered 
that Woods Hole has been recently reforested,! a disturbance which 
might easily have resulted in a local change in dominance of Amelan- 
chier types. All things considered, therefore, the assumption that the 
strain of Amelanchier in question originated by crossing, perhaps 
many years ago, and is now locally dominant, becomes very probable. 
In addition to this case at Woods Hole, at least two other very similar 
cases have been brought to the writer's attention during the summer. 
These examples illustrate very well the care necessary before a con- 
clusion is reached that a certain local type cannot be the result of 
crossing. | 
In order to avoid confusion, it may be well to mention again that 
in the illustrations of Amelanchier in the July Rnopona, the coarse 
teeth of the first three species and the fine teeth of the other species 
are not so well brought out in the plates as in nature. 
1 Reforestation at Woods Hole, Massachusetts,— A Study in Succession, M. A. 
Chrysler. Ruopona VII, 121, July, 1905. 
