iij'i
Substance between membranaceous ami cartilaginous, widely reticulated
on tbe surface, but with an otherwise dense structure. In
drying it scarcely adheres to paper. Colour a pink-red.
Mrs Griffiths has well observed that this plant at first sight resembles a
small mass of Conferva rubra of the older authors. It appears to be
extremely rare, and I believe has been found only in Devonshire by
the lady above mentioned, whose good fortune it is to find the rarest
Algce in their most perfect state. It is to her kindness that I am indebted
for specimens with both kinds of fructification. The mature fructification
she finds in September and October; but specimens occur as
early as May, so that it probably exists in some state or other throughout
the greater part of the year.
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G e n u s X X IX . ODONTHALIA, Lyngh. Tab. X III.
G e n . Ch a r . Frond plane, between membranaceous and cartilaginous,
dark vinous red, witli an imperfect or obsolete
midrib, and alternately toothed at tbe margin. F ru c tification,
marginal, axillary, or in the te eth : 1. capsules,
containing pear-shaped seeds, fixed by tlieir base; 2.
slender processes containing ternate granules.
K
tifS- iti
''iiriilt'ir iHf-
O b s. In adopting this genus, invented hy Lyngbye for the sake of
Fucus dentatus of Linnæus, I propose to extend it to the Fucus co-
rymbiferus of Gmelin, which agrees entirely in habit and in the dense
structure of the frond. According to Agardh’s system, they form a
part of his genus Rhodomela, to a certain extent only characterised
by its fructification, but in no other respect ; as it comprehends plants
with flat and cylindrical fronds, of different classes of colour, some
dense, and others singularly lax in their structure. M. Gaillon has
also admitted Fucus cirrhosus of Turner, which if not. indeed the
Thamnopliora corallorhiza of Agardh [Fucus corallorhiza. Turn.),
certainly belongs to, the same genus.
The generic name is compounded of two Greek .words, signifying a
tooth and the sea, expressive of the dentate, margin of the frond, and
its place of growth.
I. O d o n t h a l ia d e n t a t a . Tab. X III.
Frond branched spreading the branches distichous alternately pinnatifid
pinnulæ toothed at their apex, capsules ovate pedunculate panicled,
in axillai-y clusters.
Odonthalia dentata, L y n g b . H y d r o p h . D a n . p . 9. t . 3 . G r e v . F I . E d in . p . 296.
Rhodomela dentata, A g . S p . A lg . v . 1. p . 370. S y s t . A lg . p . 196. S p r e n g . S p . P I . v . 4 . p . 342.
Delesseria dentata, L am o u r . E s s a i, p . 36.
Fucus dentatus, L in n . S y s t. N a t . 2. p . 718. T u r n . S y n . F u c . p . 149. H i s t . F u c . t . 13.
S m . E n g . B o t . t . 1241.
H a b . In the sea, growing on rocks. Perennial. Found more or
less at all seasons, but producing fructification from January to March.
Coast of Yorkshire, Hudson. Coast of Durham and Northumberland,
rare, Winch. In the Frith of Forth, and on the coast of Iona, plentifully,
Lightfoot. Orkney, Rev. C. Clouston. Isle of Bute. Coast of
Ireland, Mr Robert Brawn. Larne near Belfast, B r Drummond.
Root a small hard disk. Fronds one or several from the same base,
three to ten inches long, much branched, furnished below with a kind
of midrib, which disappears in the upper part : The branches spreading
in such a manner as to form a roundish general outline, pinnatifid
with short alternate erecto-patent divisions, cut or dentated at their
apex ; including these short pinnulæ, the branches are almost half
an inch in breadth. Fructification of two kinds :—1. ovate minute
transparent capsules, on slender branched peduncles, in the axils of the
pinnulæ, and containing clavato-pyriform pink seeds, fixed by their
base to the bottom of the capsule, at length separating and escaping.
2. slender minute linear-lanceolate seed-leaves, or processes, solitary or
in branched clusters arising from the margin of the frond (mostly from
the axils), resembling delicate ciliæ, and containing two rows of roundish
ternate red granules.
Substance in mature fronds more cartilaginous than membranaceous,
adhering imperfectly to paper in drying. The structure is dense, and,
under a high magnifying power, minutely reticulated or areolated-
Colour rose-red in the youngest plants, afterwards dark vinous or
brownish-red, and nearly opake. The fructification of both kinds almost
colourless, excepting the seeds and granules.
This is a very beautiful species, and confined in this country, as far
as I know, to the northern shores. It has not been my fortune to meet
with the urceolate capsules represented in “ Fnglish Botany,” and Mr
Turner’s Historia Fucorum. Those I have described are of common
I