H ab . In the sea. Biennial? Thrown ashore a t Yarmouth, Mr
Mason. Frith of Forth, and Isle of Bute, in summer.
Root fibrous. Stem half an inch to an inch and a half long, filiform,
cylindrical at tbe base, compressed upwards, and expanding into an
ovate or ovate-oblong frond, one to two feet long or more, and six to
twelve inches wide. Substance almost membranaceous, semitransparent.
Colour pale olivaceous or greenish brown. In drying it does
not adhere to paper, and becomes thin and membranous and acquires a
yellowish liue.
I have very considerable doubts regarding the validity of this species.
The fructification is totally unknown, and the only characters of any
consequence are tlie very short stem, and form of the frond. Bishop
Gunner and Agardh describe the margin as undulated : I have found
it sometimes quite even. The substance, which Agardh considers as
more membranous than L. saccharina, does not appear to be a decisive
feature; for the latter has sometimes, even when ten or twelve feet
long, an equally membranous frond.
4. L a m in a e ia s a c c h a r in a .
Stem cylindrical compressed upwards and expanding into a cartila-
gino-membranous linear or linear-oblong attenuated frond.
Laminaria saccharina, L am o u r . E s s a i, p . 22. L y n g b . H y d r o p h . D a n . p . 21. t . 5. Ag.
S p . A lg . V. 1. p . 117. S y s t. A lg . p . 272. G re v . F I . E d in . p . 282. S p r e n g . S p . P I. v . 4.
p . 325.
F u a ts ‘saccharinus, L in n . S p . P I . p . 1630. S t a c k h . N e r . B r i t . t . 9. T u m . S y n . F u c .
p . 198. H is t. F .uc. p . 163. Sm . E n g . B o t. t . 1876.
H a b . In the sea. Perennial. Very common.
Root composed of clasping fibres. Stem fi-om a few inches to several
feet in length, from a quarter to about half an inch in diameter, expanding
into a simple ensiform frond, two to ten feet or more in length,
and two to sixteen inches in width ; sometimes quite even, at others
beautifully waved and curled at the margin, and very frequently bul-
lated, rugose, and thickened in the centre. Fructification, according
to Turner, composed of minute oblong brown seeds mixed with filaments,
and forming irregular spreading patches in the middle of tlie
frond, which is then twice as thick as usual.
Substance varying according to circumstances from cartilaginous to
coriaceous, sometimes even to membranaceous. Colour olivaceous
brown, often with a pale yellow or reddish tinge. In drying it does
not adhere to paper.
What are the real specific characters of this plant, or whether more
than one species be included under the name, I confess myself utterly
incapable of deciding. It has a most extraordinary range both in regard
to length and breadth : then, it is sometimes opake, and so thick
as to be rigidly coriaceous, sometimes so thin as to be transparent and
membranous. Sometimes it is even and plane at the margin, at others
wrinkled and bullated along its whole length, and waved at the margin.
At the insertion of the stem the frond is tapering, rounded, eleven
somewhat cordate. Bory de St Vincent has described two new
species, L. longipes and cornea, which, he says, have been hitherto
confounded with L. saccharina. Mr Turner’s figure, he observes, represents
a variety of his L. cornea. I have in vain attempted to trace
this species, but find the appearances I have above enumerated subject
to every combination. At the same time, it must be granted that individuals
might be selected which appear to be specifically different—
so long as the intermediate states are kept out of sight. In the Isle of
Bute I observed many specimens cast ashore ten feet long, and more
than twelve inches wide, very thin and transparent, of a very pale
reddish colour, hardly at all wrinkled in the centre, but waved at the
margin in so uncommon a degree, that a portion of the frond measuring
one foot in length in the middle, had a corresponding margin of
between four and five feet ! In other specimens of a similar size and
form, the substance was corneous.
A contraction which occurs in the frond of this species, as well
as in L. digitata, Bory de St Vincent makes a character of the variety
/3 of his L. cornea, which, he says, is longer, greener, and less
corneous when dry than var. « ; but I have specimens exhibiting the
contraction, of all forms and dimensions, even from one inch to nine
feet in length ; and in some, the contraction occurs neai- the base—in
others almost quite at the extremity ; in regard also to the substance of
these individuals, some are quite membranaceous, some quite corneous.
It cannot therefore be considered of any value as a specific character.
I may observe in this place, that we may infer from the presence of
the contraction in exceedingly young plants, that it does not always,
at least, arise from an effort in the vegetating power to replace an old
by a new frond. My observations upon this species in a growing
state, induce me to think that it changes its appearance in many respects,
in proportion to its age ; and that a plant in its second year
might almost be taken for another species. Before this Work shall
reach a second edition, I hope to determine this question.
c