32 ° ENGLISH BOTANY, 
upper leaves are submerged and pellucid, and similar to the lower 
ones in shape and texture, or of some intermediate form between this 
and that previously described. Stipules very long, blunt, not winged — 
on the back, scarious, with numerous fibres. Peduncles axillary, long, 
rather slender, not enlarged towards the apex. Fruit unknown. Plant — 
(when dried) dull green; the floating leaves tinged with reddish- 
brown. 
Found by Mr. Thomas Kirk in the Ballinabrack river at Ma’am, co. 
Galway. 
Ireland. Perennial. Summer, Autumn. 
A very puzzling plant, differing from any described species, thoug’ 
I have some suspicion that it may be a very luxuriant abnormal fo 
of P. polygonifolius, growing in deep running water, but, unfortu- 
nately, I have not been able to examine fresh specimens: the chief — 
difficulty of combining it with P. polygonifolius exists in the branching 
of the stem which connects it with the heterophyllus group. Th 
large stipules indicate an affinity with P. natans, but they have the 
fibres less numerous and not so strong, and the apex much less acute ;_ 
the floating leaves are 2 to 4 inches long, and very closely resembl 
those of P. polygonifolius, var. pseudo-fluitans, but the submerged leay 
are much longer, often 1 foot or more by 4 to 2 inch broad, with mo 
closer longitudinal and no apparent petiole, and are not narrowed 
the base into an evident petiole. I have seen but one specimen i 
flower which is in Mr. Borrer’s herbarium; the peduncle and spik 
closely resemble that of P. polygonifolius, var. pseudo-fluitans. 
Professor Babington refers this to P. sparganiifolius of Liistadius am 
Fries, but I have compared it with authentic specimens of this pla 
from both these botanists in the Kew Herbarium, and cannot agree 
with his conclusion. The stem of the true P. sparganiifolius - 
ae oe 
as described by Fries, perfectly simple, ahd the leaves bright grass 
green when dried: these specimens are without floating leaves, so 1 
cannot compare them with those of the Irish plant; but Fries says 
that floating leaves, though sometimes deficient, are however nee 
sary, as the plant, when destitute of them, is always sterile. The 
flowering specimen of the Galway plant in Mr. Borrer’s herbarium i 
destitute of floating leaves. 
I have seen too little of the Irish plant to venture to affirm it to 
be specifically distinct from P. polygonifolius, so that, though convinced 
it is not the P. sparganiifolius of Liistadius, I keep it under this name 
for the present, though much tempted to designate it P. Kirkii, 
its discoverer. 
9 
Ribbon-leaved Pondweed. . 
