486 PROCEEDINGS OF THE AMERICAN ACADEMY. 
achene of the European Z. ovata (Figs. 9,10) is obovate or inverted- 
pyriform in outline, and it is about three fourths as high and two thirds as 
broad as the obovate or cuneate-obovate achene of the typical American 
plant (Figs. 4 to 7) which commonly passes under that name. The 
tubercle of true Z. ovata averages four sevenths as broad as the achene, 
while that of the American plant equals the achene in breadth. Though, 
as already stated, the European H. ovata and the American plant 
recently united with it are not readily distinguished by superficial 
characters, the apparently constant differences in their achenes and 
tubercles are sufficient to justify us in regarding our own plant as dis- 
tinct from that of Europe, and in restoring to it the distinctive name 
Eleocharis obtusa, under which it was so long known to American 
botanists. 
Although the common American plant, which, for the last three de 
cades, has passed as Eleocharis ovata, proves on critical study to differ 
from that species in certain well marked and constant characters, the true 
E. ovata of Europe is not entirely wanting in our American flora. The 
American plant, however, which not only in habit but in the characters 
of achene and tubercle closely matches the European specimens and 
plates, is as yet known from only four northern stations, in New Bruns- 
wick, Maine, Vermont, and Michigan. In these specimens, in habit and 
achenes undoubtedly Z. ovata, the oblong or ovate-oblong scales are 
very dark chestnut-brown or purplish, distinctly darker than is usual in 
E. obtusa. 
In October, 1878, Mr. E. H. Hitchings collected in Dedham, Massa- - 
chusetts (presumably in Purgatory Swamp), an Lleocharis which has 
proved unusually puzzling to those who have subsequently worked upoB 
the genus. Two sheets of the plant, showing large and small specimens, 
are preserved in the Gray Herbarium, where they have been frequently 
shifted from one species cover to another. Originally Dr. Gray wrote 
upon one of the sheets, a “remarkable form, I think, of Eicocharis inter- 
media.” Subsequently both sheets were referred by Dr. Watson to 
E. obtusa ; but when studying the plants in the preparation of his syn0P” 
sis of “The Genus Eleocharis in North America,” ! Dr. N. L, Britton tT 
ferred the two Dedham sheets to different species, the smaller specimens 
to EZ. glivacea, the other to HZ. palustris. Why the two sheets should be 
_ thus separated we cannot make out. They are, to be sure, hardly iden- 
tical in size, but in general habit, scales, and achenes they are the same, 
1 Jour. N. Y. Microsc. Soc., V. 95-111. 
