36 ENGLISH BOTANY. 
fibres. Peduncles axillary and terminal, rather short, stout, thickened 
towards the apex in fruit. Sepals with their lamina rhombic-orbicular. — 
Fruiting-spike dense, oblong-cylindrical, many-flowered. Nuts green, 
rather large, acuminated, slightly compressed, nearly straight along 
the upper margin, semicircular and 3-keeled on the back, terminated 
by a short be ak, forming a continuation of the apps margin. 
anes green, or eed Ww ith reddish. 
Tn pools and lakes. Local, but widely distributed, extending from 
the south of England to Orkney and Shetland, though wanting i 
many counties. Not unfrequent in Ireland. 
England, Scotland, Ireland. Perennial. Summer, Autumn. 
Stem 2 to 4 feet long, with very numerous rather short barre 
branches below, and at length producing stolons from the axils of the 
lower leaves. Submerged leaves widely channeled; those of the main 
stem 1 to 3 inches long, those of the branches cenerally much smalle 
Stipules sometimes with two of the ribs stronger than the other, but 
quite as often with them all nearly equal. Floating leaves 1 to 2§ 
inches long, very similar to those of P. polyg gonifolius, but rather more 
coriaceous, and quite flat before they have attained their full size, 
while in P. polygonifolius they remain rolled up into a funnel un 
they are almost full grown: in some localities, however, floating leaves 
are never produced. “Peduncles 1 to 3 inches long, thick, and enlarge 
at the apex below the spike—greatly so when in fruit. Fruit spikes 
to 1} inch long. Fruit about } inch long. 
Various-leaved Pondweed. 
German, Grasartiges Samkraut. 
SPECIES IX—POTAMOGETON NITENS. Web. 
Pirate MCCCCVILI. 
Reich. Ic. Fl. Germ. et Helv. Vol. VII. Tab. XXXIV. Figs. 60 to 62. 
D. Moore, in Seemann’s Journ. Bot. 1864, p. 325. 
Stems rather slender, sparingly branched, the lower branches barren 
Leaves almost all alternate and submerged, sessile and semé 
amplexicaul, spreading-recurved, more or less folded longitudinally, 
short, oblong-lanceolate or strapshaped-lanceolate, rounded at the base, 
acute, more or less undulated but not serrate at the margins, tra 
pee! with 7 to 15 a aay ribs connected by numerous transverse 
