s6o [ 2466 ]
R I V U L A R I A vSrticillatau
Whorled P in k Rivularia*
CRYPTOGAMIA Algae.
Gen. Char. Frond gelatinous, firm, destitute of an
external cuticle. Fructification among jointed filaments,
lodged in the substance of the frond.
Spec. Char. Cylindrical, much branched, very gelatinous,
pale p in k ; branches alternate ; the ultimate
ones very numerous, of equal thickness.
Internal filaments whorled, repeatedly forked.
Fruit obovate, lateral.
Syn. Ulva verticillata. With. v. 4 . 1 I f . Hull. 3 1 3 .
F o u n d last July, on the beach at Brighthelmstone, by Mr. W.
Borrer. Miss Hutchins sent a drawing of a plant of the same
Species to Mr. Turner* from Ireland, observing that it was “ the
most gelatinous plant she had ever seen.” From this drawing
we have copied the highly magnified fructification.
The colour when fresh is a pale pink, which becomes somewhat
darker by being kept out of the water. Several very compound
stems arise from one root. The branches are all alternate;
the smaller ones pretty exactly cylindrical and obtuse, formed of
innumerable close whorls, of repeatedly branched, taper-pointed,
jointed, pink filaments, set upon a jointed, still paler, stem, the
whole enveloped in mucilage, which renders it very slippery. The
capsules or seeds are obovate, red, standing solitary and laterally
near the extremities of these fine filaments. We see no reason
to, doubt this being the Ulva verticillata of Withering, for which
several botanists have taken it.—Mr. Borrer observes that, when
floating, it considerably resembles Fucus Wigghii, t. 1165,
which is a Rivularia ; and Mr. J. D. Sowerby noticed the ultimate
branches, in that situation, to he all recurved.
2466
C kt /. fy f't.