2847
POTAMOGETON longifolius.
Long-leaved, Pondweed.
TETR ANDRIA TETR AG YN IA .
Gen. Char. Flowers sessile upon a spike which
issues from a sheathing bractea. Perianth
single, of 4 scales. Anthers sessile, opposite to
the scales of the perianth. Pistils 4, which
become 4 small nuts. Embryo curved.
Spec. Char. Leaves all elongate, lanceolate, attenuated
below, apiculate, entire. Stipules winged.
Nut —. Spike few-flowered ; flowers subver-
ticillate, distant. Peduncle very long, thickened
upwards.
Syn. Potamogeton longifolius. Gay in Gaud. FI.
Helv. v. 1. 473. Syn. 123.
S t e m s long, with long, slender, scarcely divided
branches, rising from deep water, round, smooth. Leaves
opposite, on the branches alternate, all elongated, lanceolate,
entire, apiculate, attenuated below into a very short
petiole, all membranous, with several longitudinal nerves
and rather distant transverse reticulations. Stipules green
lanceolate, with two narrow longitudinal wings. Spikes
about an inch long, with few subverticillate, distant flowers,
upon a very long (6—8 inches,) curved, much thickened’
solitary peduncle. The fruit has not yet been noticed, and
is a great desideratum.
This curious species was accidentally gathered in August
1835, in Lough Corrib, Galway, Ireland, by my friend Mr.
John B a ll; and during the summer of 1838 the same