28 ENGLISH BOTANY. 
Fruiting-spike cylindrical, many-flowered, dense. Fruit reddish, small, | 
roundish-obovate, slightly compressed, convex on the upper margi 
semicircular and slightly keeled on the back, with a short terminal | 
beak. Leaves dull olive-green, often tinged with reddish-brown. 
Var. a, genuinus. 
Prate MCCCC. 
Lowest leaves narrower and thinner in texture than the upper ones 
which are rounded or subcordate at the base. 
Var. 2, pseudo-fluitans. 
Lower leaves membranous, elliptical-strapshaped, attenuated 
each end; floating leaves subcoriaceous, gradually attenuated inte 
the petiole. 
Var. y, ericetorum. 
Leaves all similar, subcoriaceous, floating or rising out of the wate 
longly-stalked, with an oval or oblong-oval or roundish lamina. 
Var. « in shallow water. Var. in deep water, Dunsappie Loch, — 
Edinburgh; Buttermere (Professor Oliver). Var. y in wet places 
chiefly on heaths, where it is extremely abundant, and generally dis- 
tributed. The distribution of vars. a and £ I am unable to give. 
England, Scotland, Ireland. Perennial. Summer, Autumn. 
A very variable plant, with the stems rarely above a span long, as 
deep-water forms appear to be rare. The leaves are very variable 
in shape, and in many cases can only be distinguished from those of 
P. natans by being less coriaceous and not having the substance of the 
leaf continued for some distance down the petiole ; the lamina, how- 
ever, is generally smaller, commonly about 1} inch long, and there 
are no grasslike petioles destitute of lamina, which are the only sub- 
merged leaves present in P. natans at the time of flowering. The 
lower leaves have a broad lamina, like the others, only usually mo a 
attenuated at the base, and of more membranous texture. ‘The 
stipules are large, as in P. natans, but much less persistent, as the 
fibres which form their ribs are less tough. The peduncles are much 
more slender, the spike shorter, rarely above 1 inch long. The fruit— 
is only about +1; or 7’; inch long, and reddish when ripe. 
Var. & very closely resembles the true P. fluitans, having long 
narrow pellucid submerged leaves, attenuated at each end, and the 
floating leaves are narrowed at the base. The shape of the sepals, 
however, is rounder than in the true P. fluitans, which has the fruit the 
size of P. natans. . 
