54 ENGLISH BOTANY. 
the upper margin, with the lateral keels more prominent than 
central one. 
Var. a, genuinus. 
Puate MCCCCXXIT, 
Reich. Ic. Fl. Germ. et Hely. Vol. VII. Tab. XIX. Fig. 30. 
Leaves and branches rather few and distant, nearly equally disposed | 
over the stem. Leaves all similar, the early ones 1-ribbed. 
Var. 6, scoparius. Wallr. 
Puare MCCCCXXIII. 
P. marinus, Huds. Fl. Angl. ed. ii. p. 77 (non Linn. Herb.). 
Tteich, Ic. Fl. Germ. et Helv. Vol. VII. Tab. XTX. Fig. 32. 
Stem at length nearly bare of leaves and branches below, ve 
leafy and much branched towards the apex at the time of floweri 
Early leaves flat, 3-ribbed; upper leaves setaceous, 1-ribbed, 
Orkney, and I have specimens from between Troon and Ayr. 7 
Var. 6, in brackish ditches. Apparently confined to England, 
where it is very plentiful in the south, and whence I have seen spe 
cimens as far north as Coatham, Yorkshire, and Rhyl, Flint. One or 
both of the forms are frequent in Ireland. . 
England, Scotland, Ireland. Perennial. Summer. 
A variable plant, with the upper leaves much narrower than those 
P. flabellatus, and composed of two united parallel tubes divided by 
transverse partitions. The early leaves, however, though much nar- 
rower than those of P. flabellatus, are sometimes very similar to the 
later leaves of that plant. The fruit is rather rounder, and has th v 
lateral keels more developed, and the central one usually indistinet. 
The spike is generally shorter, and with the flowers more crowd ed 
towards the apex. The whole plant is also more deeply tinged with 
olive-brown. 
The P. marinus of Hudson seems to be P. eu-pectinatus, 
scoparius, as that is the only form which grows in Sheppey, where 
is very abundant: this form connects var. « with P. flabellatus. 
Fennel-leaved Pondweed. 
French, Potamot en dents de peigne. German, Fadenblattriges Samkraut. 
