188 BOTANICAL GAZETTE [SEPTEMBER 
by Holm, and was not published until in 1900, when it was men- 
tioned in the Szxth List of Additions to the Flora of Washington? 
Not until 1893 were specimens recognized as /svetes saccharata 
Engelm. secured away from Canby’s stations on the Wicomico 
and Nanticoke Rivers. In this year T. Chalkley Palmer discov- 
ered it near the western end of the Delaware and Chesapeake 
Canal in Back Creek, a tributary to Elk River, nearly 140*™ 
north of the type locality. During the next two years he dis- 
covered it at several other points in both Elk and Sassafras 
Rivers. These collections formed the subject of an interesting 
account published in the BoranicaL GAZETTE in 1896.3 
The only new stations which have been published since 
Palmer’s account are given in the Sixth List of Additions to the 
Flora of Washington, where, besides the reference to Coville’s 
Mount Vernon station above mentioned, two new localities are 
recorded for the upper Potomac. Along with the publication of 
these stations were given the descriptions of two new varie- 
ties: var. Palmeri A. A. Eaton, based upon Palmer’s material 
from Lloyds Creek, Sassafras River; and var. reticulata A. A. 
Eaton, based upon several collections, including that of Vasey 
and Coville (1888) from the Hunting Creek station, Alexan- 
dria, Va. 
Since the publication of Palmer’s paper on Isoetes, that col- 
lector has located several new stations which are here published 
for the first time. The most notable of these, and the only one 
outside of the Elk and Sassafras Rivers, is about 25™ north of 
the Havre de Grace light at the mouth of the Susquehanna River, 
and therefore at the very head of the bay. 
I believe these are all the localities known for the species 
before my collections of the past summer. My work was limited 
almost entirely to the west side of the bay, and my collections of 
Isoetes saccharata were made in the western tributaries and along 
the shore of the northern part of the bay, my most northern sta- 
tion being only 500™ from Palmer’s Havre de Grace station, thus 
making the circuit about the head of the bay virtually complete. 
? Proc. Biol. Soc. Washington 14:49. 19 Je 1001; 
3 BoT. GAZ. 21 : 218-223. 1896. 4 Loc. cit. 
