' W
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k
110
Substance cartilaginous, tender, soon becoming flaccid, and decomposing
; adhering to paper in drying, and retaining its colour. Colour
deep purplish brown, reddish, or green. Taste often, but not always,
hot and biting.
In the whole series of the British Marine Algæ there is no species
which puts on more distinct appearances tlian the subject of the present
description, and yet, like Mr Turner, I am convinced that the varieties
form really but one individual. During my late residence at Sidmouth,
Miss Cutler gathered a plant, which she was kind enough to
send me in a recent state, and which at first so effectually perplexed
me, that I imagined it might eventually lead to the formation of a new
genus. The branches and branchlets were cylindrical, and terminated
by a saucer-like cavity about twice tbe diameter of the branches, and
very similar to the shield of a lichen. This was uniformly filled with
numerous linear simple or divided bodies vertically arranged ; apparently
composed of very short filaments surrounding a longitudinal
axis, the whole terminated by a number of round pellucid lobes.
These bodies will be found represented at Fig. 9. in Plate XIV.
Upon examining her collection, Mrs Griffiths found some Cornish
specimens exhibiting the same appearance. And a short time afterwards,
I was still more surprised to find these bodies in some of
the more common varieties; only with this difference, that, instead
of a shield-like cavity, there was a regular capsule. This kind of
capsule is twice or thrice the size of the true capsule, but is of the
same form, and situate on the same part, but always in distinct individuals.
On pressing one of these capsules on the table of the micro-
scope, the little bodies above described escape by the terminal pore in
profusion.
A curious appearance has also come under my observation, in some
specimens which seemed to contain ternate granules. In the place of
ternate granules, however, I found oblong red granules imbedded from
the surface to the veiy heart of the branchlet, in a longitudinal direction,
with their lower extremity attenuated into a pellucid short stalk.
It would therefore appear, that, in a physiological point of view, the
ramuli, in this case, had failed to develope their capsules externally,
and had produced seeds within their own substance ; and that such
specimens are not truly granuliferous, but abortive capsuliferous
plants.
Laurencia pinnatifida was formerly (and perhaps still is) eaten ip
Scotland, where it is known by the name of Pepper-dulse.
2. L a u r e n c ia o b t u s a .
Frond cylindrical, repeatedly pinnated, the branches mostly opposite
nearly horizontal, ultimate pinnulæ very short, clavate.
Laurencia obtusa, L am o u r . E s s a i, p . 42.
Laurencia intricata, L am o u r . E s s a i, p . 43. t . 3. f. 8. 9.
-'Sardh.
Laurencia cyanosperma, L am o u r . E s s a i, p . 43.
Chondria obtusa, Ag . S p . A lg . v . 1. p . 340. S y s t. A lg . p . 202. G r e v . F I . E d in . p . 290.
S p r e n g . S p . P I . v . 4. p . 341.
Fucus obtusus, H u d s . F I . A n g . p . 586. T u r n . S y n . F u c . p . 43. H is t. F u c . t . 21. Sm .
E n g . B o t. t . 1201.
H a b . In the sea, parasitic on the larger Algoe. Annual. May to
October. Coasts of Devonshire, and at Hastings, Hudson. Near Fxmouth,
Goodenough. Near Torquay, Mrs Griffiths. Weymouth,
Mr Fryer. Caswell Bay and the Worms Head, Mr Dillwyn. Sunderland
beach, Mr Weighell. Isle of Wight, Stackhouse. Flam-
borough Head, Mr Teesdale. Coasts of Ireland, Turn. Hist. Fuc.
Bangor, Ireland, Dr Drummond. Frith of Forth, very rare.
Root a minute disk throwing out a few creeping fibres. Fronds
solitary or several from the same base, three to six inches long, cylindrical,
filiform, half a line, more or less, in diameter, composed generally
of a single flexuose stem, much branched from the very base ;
branches nearly twice or thrice pinnate, horizontal, lax, the lower ones
one to three inches long, the remainder becoming gradually shorter
upwards, the subdivisions mostly opposite (sometimes ternate) ; the
ultimate branchlets one or two lines in length, approximated, club-
shaped, simple and truncate, or somewhat lobed and rounded. Fruc-
tification : 1. ovate capsules containing stalked pear-shaped seeds on
the younger branches ; 2. ternate granules in the club-shaped callous
ramuli.
Substance cartilaginous, tender ; adhering to paper in drying. Colour
a yellowish fugitive semitransparent pink. The main stem is often
colourless, while tbe rest is quite pink.
This is a far more delicate plant than the preceding, both in substance,
habit, and colour. Its lax, nearly horizontal and mostly opposite
branches, are sufficient to mark it while growing.
Mr Turner describes a variety with the ramuli longer than usual,
and merely rounded at the extremities without being incrassated.