when ripe, obovate, rounded at the end with a minute subterminal
apiculus, wrinkled when dry. Receptacle globose,
setose.
The plant before us belongs to a most difficult group of
species or varieties, which well deserve to have that attention
paid to them in Britain which has resulted in the discovery of
numerous allied forms in France. Our plant is undoubtedly
that of DeCandolle, but not of Nolte. The R. tripartite of
Cosson and Germain {All. FI. de Par. t. 1. f. 7, 8) can
scarcely be intended for our plant, unless a wrong carpel is
there figured, and it may be remarked that all reference to
those cuts is omitted by Godron in his peculiarly elaborate
account of these plants in the Flore de France. It should
however be stated that specimens named R. tripartitus by
JVL Lenormand, gathered at Angers, show great variation in
the position of the remnant of the style in the ripe carpels. In
most cases it is as represented in our plate, but in others
in the same specimen its position is nearly that shown in the
Atlas Thed ew laan Ft loofr seu dbem Perasreids. lea' ves on the British plant causes
it to seem more nearly allied to R. hederaceus than is really
the fact; it is probably deprived of them by living in shallow
water: its setose receptacle is a sufficient distinction. Its
true allies are some little-known plants, viz. R. ololeucos
(Lloyd), R. Petiveri (Coss. et Germ.); R. Baudolii {Godr.),
Batrachium marinum (Fries); and R. confusus (Godr.), R. tripartitus
(Nolte), R. Petiveri (Koch in St. Deutsch. FI.).
R. confusus and R. Baudotii agree with R. aquatilis in having
greatly adnate stipules; R. ololeucos has the free stipules of
our plant, but differs from it by having longer peduncles,
much larger and wholly white petals, and a style enlarged at
its base and persistent. In the absence of personal experience
of the characters of these plants, we do not venture to express
an opinion upon their claims to rank as species: if only varieties,
they must be considered as well-deserving of attention.
We are indebted to its discoverer, Mr. H. C. Watson, for
the specimens figured, which w'ere gathered by him in shallow
ditches on the sandy and peaty heath near Claremont House,
Surrey, flowering in May; the writer has found it this summer,
1848, near Haverfordwest.—C. C. B.
A magnified dry nut is figured to show the shape and transverse
wrinkles.