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C E R AM IUM PATENS.
Spreading pinnated Ceramium.
C la s s a n d O k d e b CRYPTOGAMIA ALGÆ, im n— N a t . Obd. A LG M , Juss.
GENERIC CHARACTER.
Fila articúlala, rosea vel purpurea, tubo simplici, capsulee globosee, sporidia numerosa
conglomerata includentes.—A g a r d h .
Filaments jointed, fine red or purple colour, composed o f a single tube :
capsules globose, containing a cluster of numerous sporidia.
SPECIFIC c h a r a c t e r .
C e r a m iu m patens ; Jilis laxe ramosis, ramis breviter pinnatis ; pinnis
horizontalibus, in ramulis patentissimis dichotome divisis.
C. filaments loosely branched, the branches shortly pinnated : pinnæ alternate,
horizontal, dichotomously divided into very spreading ramuli.
H a b . In the sea. Rejectamenta in Etterick Bay, Island of Bute, May.
Frond two or three inches in length, slender, delicate, rose-coloured, sending
off a few alternate lax branches. Stem and branches set with alternate
horizontal pinnæ, pre tty closely arranged (a pinna being produced
from every th ird articulation), and not two lines in length. These
pinnæ are several times divided in a dichotomous manner, two articulations
generally occurring between the divisions, all of which form
nearly rig h t angles, and thus crossing one another, give a reticulated
appearance to the pinnæ.
Of this beautiful aud siugular plaut, I regret to say, I
fouud ouly oue speeimeu, aud that uot iu fructification. It is,
however, so strikingly characterized by its habit, and the peculiar
division of the frond, that, even in its present state, it admits
of a very satisfactory definition.
It belongs to the fourth tribe Bosei of A g a r d h ’s division
of the genus Ceramium.
Fig. 1. C, patens, natural size. Fig. 2. Portion o f stem and pinna;. Fig. 3.
Ditto, with a pinna. Fig. 4. Portion o f the lower part o f the stem; magnified.