SU) 
Or 
NATADACEZ. 
England. Perennial. Autumn. 
A small slender plant 9 to 18 inches long. Leaves rarely above 
1} to 2 inches long, the lower ones bearing considerable resemblance 
to those of P. acutifolius, the upper to those of P. rufescens in minia- 
ture. oonmels 4 to 2 inches long, slender. Head of flowers rarely 
so much as Linch long. Although Mr. F. M. Webb was kind enough 
to send me numerous fresh specimens of this plant from Anglesea, 
gathered as late in the year as September, I have never seen the fruit, 
as all Mr. Webb’s specimens were in flower. 
A very distinct species, which has been called in question, from the 
Anglesea plant being combined with forms of P. heterophyllus, 
P. nitens, and P. polygonifolius. Smith appears to have really known 
the plant, though he has erroneously given two Scotch localities on the 
authority of Hooker's “ Flora Scotia.” 
Lanceolate Pondweed. 
SPECIES VIIL—POTAMOGETON HETEROPHYLLUS. Schreb. 
Prats MCCCCVI. 
Reich. Ic. Fl. Germ. et Helv. Vol. VII. Tabs. XLI. XLIT. XUITI. Figs. 71 to 78. 
Billot, Fl. Gall. et Germ. Exsice. No. 1066. 
P. gramineus, Fries. Mant. i. p. 36, and Summ. Veg. Scand. 68 (67). Koch. Syn. 
Fl. Germ. et Helv. ed. ii. p. 777. Gren. & Godr. Fl. de Fr. Vol. III. p. 314. 
Crep. Man. FI. Belg. ed. 1. p. 302 (non Linn. Sp. Pl. nec Herb. !). 
Stem wiry, much branched, the lower branches barren. Leaves 
mostly alternate, submerged, sessile, not at all amplexicaul, spreading 
or very slightly recurved, nearly flat, short, elliptical-strapshaped or 
oblong-strapshaped, rather gradually attenuated at each end, often more 
or less undulated, not denticulate at the margins, translucent, with 7 
to 11 longitudinal ribs connected by numerous oblique veins, and with 
several rows of rather elongate-cancellate areolations along the sides of 
the midrib ; upper leaves opposite, sometimes floating, and then with 
long petioles, oval or oblong-elliptical, rounded or abrupt at the base, 
rarely attenuated into the petiole, coriaceous, of the same texture as 
the petiole, with numerous longitudinal ribs connected by numerous 
cross veins, which are indistinctly perceptible if the leaf be held against 
the light, when also the small areolation is indistinctly perceptible 
distributed equally over all the leaf : sometimes the upper leaves are 
translucent and subsessile, and similar to the lower ones, except that 
they are more narrowed towards the base. Stipules small, except the 
upper ones, which are broad, acute, not winged on the back, scarcely 
scarious, except at the edges, and with numerous strong longitudinal 
F2 
