NAIADACEZ. 31 
Var. 8, homophyllus. 
Leaves all pellucid, none of them floating. 
In ditches and slow streams or pools. Rather local, but generally 
distributed. It is, however, doubtful if it extends to the extreme 
north of Scotland. Rather rare in Ireland, but occurring from south 
to north of the island. 
England, Scotland, Ireland. Perennial. Summer, Autumn. 
Stems springing at intervals from the creeping rootstock, simple, 
6 inches to 3 feet long. Lower leaves 3 to 6 inches long ; lamina of 
the upper or floating leaves 1} to 3 inches long. Fruiting spike 3 to 
2 inches long, usually much shorter than the peduncle. 
The acuminated fruit, scarcely at all compressed on the sides, dis- 
tinguishes P. rufescens from the deep-water forms of P. polygonifolius, 
in which also the lower leaves are more attenuated towards the base 
and smaller, the upper ones not attenuated into the petioles, and more 
coriaceous, the petioles much longer, and the whole plant is less tinged 
with reddish-brown than in P. rufescens. 
Reddish Pondweed. 
French, Potamot rousdtre. German, Réthliches Samiraut. 
Suzs-Section IJ].—LUCENTES. 
Stem branched, the flowering stem giving off barren branches in its 
lower part. Peduncles axillary or terminal. 
SPECIES (?) V—POTAMOGETON “SPARGANIIFOLIUS.” Bad. 
Prats MCCCCIII. 
Bab. Man. Brit. Bot. ed. vi. p. 363 (ew parte) (non Ldst.! nec Fries !). 
P. Kirkii, mihi, MS. 
Stems round, much branched; the lower branches barren. Leaves 
mostly alternate, submerged, sessile, very long, linear, attenuated at 
the base, and more abruptly so at the apex, not denticulate, trans- 
lucent, with numerous longitudinal ribs connected by few and distant 
transverse veins, and with several rows of greatly elongate-cancellate 
‘areolations along the midrib; upper leaves sometimes floating. , longly 
‘stalked, elliptical or oblong-elliptical, gradually or the upper ones more 
abruptly attenuated into the long petiole at the base, subcoriaceous, of 
the same texture as the petiole, with the ribs and cross veins conspicuous 
if the dried leaf be held against the light, when minute areolation is 
indistinctly perceptible all over the leaf between the ribs: often the 
