37 
This species in our country propagates itself mainly by winter 
buds, of which there are two kinds. The rarer kind is spicular in 
form, being simply a fragment of the stem, shrunken or sharpened 
at the ends, with 2-6 buds upon it in the axils of the decayed 
leaves. The more common form is a thick, rigid body composed 
of the ends of the branches or stems, in which the upper portion 
is swollen, hardened and surrounded by the bases of the leaves, 
which are also much enlarged and indurated, and reduced to a 
triangular shape, several buds being left in the axils. The lower 
end becomes sharpened and is so easily detached that a mere jar 
shakes it off the stem. The whole bud looks like a burr,and when 
separated from the stem floats away bottom side up or sinks into the 
mud. The new plant is formed by the development of one of the buds 
which throws out roots asit grows. It occurs in fresh and brackish 
or tide water. Confined to a strip along the Atlantic coast from 
Arlington, Mass., to James City, Virginia. It also runs inland in 
fresh water as far as Lancaster, near the Susquehanna River, Pa. 
(Porter), and the Lakes Keuta and Seneca, in the centre of New 
York. Introduced from Europe, where. it is common.* (Plate 
XLIV. The two kinds of propagating buds are shown on the 
left.) 
21. POTAMOGETON ZOSTEREFOLIUS, Schum. Enum. Pl. Saell. 50, 
168 (1801). 
P. complanatus, Willd. Mag. Berl. Fl. iii. 248 (1809). 
P. compressus, Fries, Nov. Ed. 2. 44 (1828), not L. Herb. 
P. cuspidatus, Schrad. in Smith’s Eng. Bot. i. 235 (1828). 
Stem very much flattened, sometimes winged, widely branch- 
ing. Leaves linear, obtuse and mucronate or shortly acute, with 
3 principal nerves and many fine ones, the midrib often compound, 
2-12 inches long and 1-2 inches wide. Stipules scarious, obtuse, 
finely nerved, soon perishing. Peduncles 177-4 inches long; 
spikes cylindrical, about % inch long, 12-15 flowered. Fruit 
obovate, with a broad base, 134-2 lines long and 134-134 lines 
wide, 3-keeled on the back, lateral keels somewhat obscure, the 
robably of recent introduction, as it seems not to have been known to the 
older ne Rafinesque, Michaux, Pursh, Nuttall, Barton and others who col- 
lected extensively in the "d where it grows during the early part of this century. 
