NAIADACER. 53 
Sus-Srecies (?) L—Potamogeton flabellatus. Bad. 
Prats MCCCCXXI. 
Reich. Ic. Fl. Germ. et Helv. Vol. VII. Tab. XTX. Fig. 31. 
Bab. Man. Brit. Bot. ed. vi. p. 366, and Phytol. Vol. IV. p. 1158. 
P. zosteraceus, Bab. Man. Brit. Bot. ed. i. p. 325 (non Fries). 
P. pectinatus, var. B, Hook. & Arn. Brit. Fl. ed. viii. p. 479. 
P. pectinatus, “ var. dichotomus, Wallr.” Reich. 1. c. p. 12. 
| ©P. Vaillantii, Rom. & Schultz.’ Teste Reich. 1.c. 
Leaves flat; the earlier ones broadly linear, 3- to 5-ribbed; upper 
leaves narrowly linear, 1- to 3-ribbed. Nuts nearly straight on the 
upper margin, with the lateral keels indistinct; the central keel 
prominent. 
In rivers, ditches, and canals, in fresh and brackish (?) water. Appa- 
rently not uncommon in England, extending north to Lancashire and 
Yorkshire, but the plant is so confounded with the following sub- 
species that it is impossible at present to give its exact distribution. 
Tn Ireland it is found near Cork, Fermoy, Clonmel, and near Straffan, 
Kildare. 
England, Ireland. Perennial. Summer. 
Rootstock creeping, springing from a small tuber. Early leaves 
3 to 8 inches long, and + to } inch wide; these leaves, however, are 
mostly decayed by the time the plant comes into flower, and the upper 
leaves are not more than 4}; inch broad, and often narrower. Flowers 
in 4 to 8 whorls, mostly 2 in a whorl. Peduncles (exclusive of the 
spike) 1 to 4 inches long; the spike itself 1 to 2 inches. Nuts } inch 
5 
long. The stipules, adhering to the leaf-stalks and forming a basal 
sheath, distinguish this plant, when not in flower, from all those of the 
preceding sections. 
The Rev. Kirby Trimmer, in the “ Flora of Norfolk,” states that in 
the Trent, by Walton-on-Trent bridge (Derby), he has “always met 
with plenty of the broad lower leaves in undecayed condition through 
the months of July and August.” 
Fan-like Pondweed. 
Sun-Srrcies (?) I.—Potamogeton eu-pectinatus. 
Pirates MCCCCXXIT. MCCCCXXIII. 
Billot, F). Gall. et Germ. Exsice. No. 3250. 
P. pectinatus, Bab. Man. Brit. Bot. ed. vi. p. 366. 
P. pectinatus, var. a, Hook.-& Arn. Brit. Fl. ed. viii. p. 479. 
Early leaves flat, linear, usually 3-ribbed; upper leaves setaceous, 
L-ribbed, composed of 2 interrupted tubes. Nuts slightly convex on 
