30 ENGLISH BOTANY. 
towards the apex, and not of uniform width, as in P. polygoni- 
folius; the lamina of all the leaves, when held against the light, 
shows a delicate areolation between the veins, the cells being largest 
along the sides of the ribs. The fruit is about +; inch long, consider-— 
ably smaller than in the last species, green, not red, with the upper 
margin straighter, and terminated by the beak, which in P. polygoni- 
folius is situated more nearly in a prolongation of the axis of the— 
fruit. In both P. polygonifolius and P. plantagineus the fruit is— 
marked with a lateral ridge on each side of the keel. 
The leaves vary in breadth, as in P. polygonifolius: in some Guern- 
sey specimens they are suborbicular. 
Plantain-leaved Pondweed. 
French, Potamot plantain. German, Wegebreitblitteriges Samkraut. 
Prtamoge len 
SPECIES IV.—POLYGONUM RUFESCENS. Schrad. 
Piate MCCCCIL 
Reich. Ic. Fl. Germ. et Helv. Vol. VII. Tab. XXXII. Fig. 56 to 58. 
Billot, ¥\. Gall. et Germ. Exsice. No. 650. 
P. fluitans. Sm. Engl. Bot. ed. i. No. 1866 (non Schrad.). 
P. alpinus, Balb. Crep. Man. FI. Belg. ed. ii. p. 302. 
tare 
i] 
es 
Se 
Stems round, simple or nearly so. Lower leaves alternate, sub- 
merged, sessile, strapshaped-elliptical, or oblong-elliptical, attenuated 
at the base and apex, not denticulate, translucent, with numerous faint 
longitudinal ribs connected by transverse veins, and with several rows — 
of large cancellate areolations along the midrib; upper leaves opposite, 
floating or rising out of the water, stalked, oblanceolate or obovate or 
obovate-elliptical, gradually attenuated into the short petiole at the base, 
subcoriaceous, of the same texture as the petiole, with the ribs and cross 
veins rather conspicuous if held against the light, when minute areola- 
tion is indistinctly perceptible all over the leaf between the ribs: more— 
rarely the upper leaves are submerged, pellucid, and similar to iu 
lower ones in shape and texture, or in some intermediate state between 
this and that previously described. Stipules large, blunt, not winge 
on the back, scarious. Peduncles axillary, rather slender, not enlarg 
towards the apex. Sepals with their lamina roundish. Fruiting-spike 
oblong-cylindrical or cylindrical, many-flowered, dense. Fruit reddish- | 
fawn colour, rather small, oval-ovoid, acuminated at the apex, ve 
convex on the upper margin, semicircular, and sharply keeled on the 
back, with a rather prominent recurved subterminal beak. Plant 
tinged with reddish-brown, especially when dry. i 
OL AE Er 
- 
Var. a, genuinus. 4 
Lower leaves pellucid; upper leaves subcoriaceous, floating. 
