1901 | Fernald, — Scirpus supinus and its Allies. 249 
of each in every stage of development were anywhere from six inches 
to two feet distant. The rock was slightly shaded by sumachs, and 
the pocket, apparently a misplaced pot-hole, was about six inches in 
diameter, with a slit in one side. The soil in it looked like ordinary 
pasture loam, finely pulverized, but with no trace of leaf-mould or 
disintegrated limestone. It must, however, have had some virtue 
as three or four inches sufficed to support the two rarities, above de- 
scribed, and a young specimen of Asplenium ebeneum. The third 
plant of A. ebenoides grew in richer soil of considerable depth. 
Unbelievers in the theory of the hybridity of A. ebenoides will find 
it difficult to gainsay the argument in its favor, which is spread on 
this grassy slope. The intermediate form of the fronds, their ten- 
dency occasionally to root at the tip, the abundance of both the sup- 
posed parent-stocks in the immediate neighborhood are matters here 
well illustrated. Furthermore, if an inability to reproduce from spores 
is any test of hybridity in a fern, additional testimony can be ad- 
duced from this source, for I have searched the section thoroughly 
and am convinced that not another plant of A. ebenoides is to be 
found in the locality. The presence of a single well-developed 
specimen with heavily fruited fronds in a perfect environment for 
the germination of spores must have some significance. The con- 
tention over the origin of this unique fern will probably cease only 
with artificial crossing of the species; this, however seems super- 
fluous when such telling evidence can be obtained from the natural 
occurrence. 
PITTSFORD MILLS, VERMONT. 
SCIRPUS SUPINUS AND ITS NORTH AMERICAN 
ALLIES. 
M. L. FERNALD. 
On September 7 Mr. E. F. Williams and the writer found on the 
sandy shores of Massapoag Lake, in Sharon, Massachusetts, a plant 
which superficially resembles Scirpus debilis, Pursh. The shining 
black achenes, however, are quite naked, even in their younger stages 
showing no trace of the perianth of retrorsely barbed bristles which 
quickly distinguishes S. debilis from the related S. supinus and S. 
Smithii A study of the Massapoag plant in connection with the 
