96 F L O R IÜ EÆ . [Rhodomenia. Plocamium.] F L O R I D EÆ . 97
I have received a specimen of tliis species from the coast of Normandy,
gathered by M. Chauvin, by whom it is marked as exceedingly
rare. It appears, therefore, that its distribution is more extended tlian
it was supposed to be.
No species that I am acquainted with, is so apt to vary in the width
of the frond and its segments. In some specimens, the whole has a
narrow linear' character, while in others there is a considerable expansion.
There is in fact as great a range as between the broad Rhodomenia
palmata and its narrow variety Sarniensis ; at the same time
it can never be mistaken after having been once seen. The colour is
brighter than in R. palmata, more fugitive, and the frond is evidently
marked with pretty large though obscure reticulations, which are sufficient
to distinguish it from that plant.
10. R h o d o m e n i a T e e d i i .
Frond membranaceous tender between compressed and flat linear
irregularly pinnated and ciliated the ciliæ like little subulate spines,
capsules spherical on the ciliæ.
Sphoerococcus Teedii, A g . S p . A lg . v . 1. p . 277- S y s t. A lg . p . 226. S p r e n g . S p . P I. v . 4.
p . 337. G r e v . C r y p t . F I . t . 356.
Gigartina Teedii, L a in o u r . E s s a i, p . 49. t . 4. f . 11. *
F u c k s Teedii, T u r n . H is t. F u c . t. 208.
H a b . On rocks in the sea. PerenniaL Lupton Cove and Tor-
Abbey rocks, Torbay, Mrs Griffiths,
Root minute, scutate. Fronds tufted, two to five inches in length,
less than a line in width, nearly cylindrical at the base, gradually becoming
between flat and compressed, pinnated, or rather pinnatifid,
with numerous branches from the very base ; pinnoe horizontal, irregular,
from a few lines to three inches in length, arising at short intervals,
bearing a second smaller equally irregular series, set with scattered
minute subulate ramuli ; all the divisions attenuated and acute.
Fructification : 1. minute, red, spherical capsules in the substance of
the subulate ciliæ, containing a mass of red, very small ovate seeds ;
2. granules imbedded in the ciliæ, on distinct individuals. Substance
membranaceous and flaccid. Colour a purplish-red. In drying it becomes
somewhat corneous, does not adhere to paper, and is often
beautifully variegated with green pink and pale purple.
A very charming marine plant, added to the British Flora, by my
often mentioned friend Mrs Griffiths, in 1811. She has not, however,
been so fortunate as to meet with the fructification, and my
foreign specimens are not sufficiently perfect to enable me to obtain a
completely satisfactory analysis. Lamouroux has figured a small portion
of the frond with imbedded granules, hut does not say whether
the granules are ternate. Should they be entire, the plant miglrt be
placed without much violence among the Gracilaria;. Mr Dawson
Turner has remarked, that it bears no small resemblance to some states
of Rhodomenia ciliata ; this applies to a more simple form of the
frond than occurs in this country, whei'e the species most likely to be
confounded with it while growing in the water, is Gelidium corneum.
My foreign specimens are finely clouded with different colours, while
the British ones are uniformly red : the latter are also rather thinner
in substance.
G e n u s XX VII. PLOCAMIUM, Lammr. Tab. XII.
G e n . C h a r . Frond iiliform, compressed, hetween membranaceous
and cartilaginous, fine pink-red, much branched,
branches distichous (alternately secund and pectinate).
Fructification of two kinds : spherical sessile capsules,
and lateral minute processes, containing oblong granules,
transversely divided into several parts hy pellucid lines.
Obs. In habit this genus is intermediate between Delesseria auA
Sphoerococcus. The frond is very narrow, much divided in a distichous
and widely spreading manner ; the structure dense. The seed-leaves or
processes containing the granules are similar in structure to the rest of
the frond, and seem rather to be a permanent continuation or ramification
of it than organs thrown out to perform the temporary purpose of
fructification. The granules themselves are very different from those
of the preceding genera of the order, being oval or elliptical-oblong,
surrounded by a pellucid limbus, and transversely divided into four or
five parts, which ultimately separate.
The generic name is derived from a Greek word, signifying hair or
a head of hair :—not a very happy appellation, for though the frond is
finely divided, it cannot be said to resemble hair.
The genus was originally proposed by Lamouroux, and continued
by Lyngbye : Agardh abolished it, but Gaillon has again restored it.