R I V U L A R I A tuberiformis.
Potatoe Rivularia.
CRYPTOGAMIA Algæ.
Gen. Char. Frond gelatinous, firm, destitute of an
external cuticle. Fructification among jointed filaments,
lodged in the substance of the frond.
Spec. Char. Frond irregularly globose, inflated, pale
brown ; white within. Seeds vertically disposed in
rows at the summits of the filaments.
C o m m u n ic a t e d by the Rev. G. R. Leathes, who found it
adhering to rocks and submarine plants on the coast of the isle
of Wight in August 1808. Mr. Turner and Mr. Sowerby
observed it nine years before at Kynance cove, Cornwall, and
the former assures us it is common about the shores of all the
Hebrides. Yet we can find no traces of its being any where
described.
When floating in the sea water it looks, as we are told,
extremely like an assemblage of young potatoes, in colour as
well as size and shape. Each full-grown plant is half an inch,
or near an inch, in diameter, of an irregularly round, or imperfectly
globose, figure, hollow, pale brown, gelatinous and
rather tender, internally white. A perpendicular section when
magnified shows the substance to be a congeries of entangled
filaments, whose upper extremities meet in a parallel order,
all on a level, at the surface, and in each of those extremities 3
or 4 brown seeds are disposed one above another. No slender
pellucid filaments extend, as in some species of Rivularia,
beyond the seeds.------This plant, when dried with due care,
adheres to paper, and preserves tolerably well, only assuming
a darker hue.