One of the most remarkable features in this species is the roughness
more or less present in the primary branches, arising from little processes
which Mr Turner justly compares to the rudiments of abortive
branches. Near the base they ai-e half a line long or more, hut decrease
in the upper part till they become mere dots. They are, in
fact, another instance of the proneness to transformation among the parts
of -these vegetables. The thin plane leaves become filiform branches,
and the dots upon them, which at first look like glands or pores on the
surface, become elongated into rigid, blunt bristles.
The colour in the branches is rather pale olive green; substance
flexible and cartilaginous.
5. C y s t o s e ir a f ib r o s a .
Frond bushy very much branched, branches filiform the terminating
branchlets (or leaves) linear plane, vesicles elliptical mostly solitary,
receptacles filiform much elongated.
Cystoseira fibrosa, Ag . S p . A lg . v . 1. p . 60. S y s t. A lg . p . 285. S p r e n g . S p . P I . v . 4 . p . ,817.
Fucus fibrosus, H u d s . F I. A n g . p . 576. T u r n . S y n . p . 93. H i s t . F u c . t . 209. S m . E n g .
B o t. 1 . 1969. L am o u r . E s s a i, p . 18.
H ab. In the sea. Perennial. Summer. Falmouth, Turner. Ilfracombe,
Goodenough. Weymouth, Pulteney. Coasts of Yorkshire
and Hampshire, Hudson. Dover, rare, Dillwyn. Yarmouth Beach,
but rarely seen, Mr Wigg. Selsey, Mr Borrer.
Root a hard spreading disk. Frond two to three feet long: stem
as thick as a swan’s quill, about a foot in length, nearly cylindrical,
set with distichous alternate undivided branches, the lower ones of which
become gradually broken off: branches bushy, subcylindrical, one or
two feet long, producing many subordinate divisions, the ultimate ones
simple or forked, plane, linear-setaceous, two lines to an inch long.
Air-vessels above two lines in length, round-elliptical, sometimes oblong,
solitary, or two or three placed at short intervals, generally towards
the base of the branchlet on which they occur. Receptacles
simple or divided, filiform, torulose, half an inch to above an inch long,
set with little setaceous plane ramuli or leaves.
The young plant, and often also the young branches, when any
happen to arise near the base of the stem, are furnished with flat
simple incurved leaves, one or two inches long, nearly linear, one or
two lines broad, having a midrib, and a paler colour. Sometimes the
whole frond bears plane linear leaves, only much smaller. The substance
is tvoody in the stem, and coriaceous in the rest of the frond.
Colour yellowish olive-green.
The vesicles of this fine species, which are three or four times wider
than the part in which they appear, and about the size of a vetch-seed,
and the bushy and somewhat harsh appearance of the frond, serve to
distinguish it at first sight.
G e n u s III. HALIDRYS, Lyngb. Tab. I.
G e n . C h a r . Frond compressed, coriaceous, linear, pinnated
with distichous branches. Air-vessels lanceolate, stalked,
divided by transverse septa. Receptacles lanceolate,
stalked, compressed. Seeds in distinct cells.
On this genus Lyngbye (the author) has conferred a name expressive
of the habit of the only known species, when growing in the water.
It is derived from two Greek words, the one signifying the sea, the
other a tree. I say the only known species ; for though Lyngbye himself
has admitted into it Fucus nodosus, I cannot conceive it possible
that they should continue to be associated. The latter is undoubtedly
a true Fucus. By Lamouroux Halidrys was considered to form a
part of the fourth section of his genus Fucus, distinguished only by
the form of the vesicle. By Agardh it is arranged with Cystoseira.
M. Gaillon not only follows Lyngbye in continuing to retain Fucus
nodosus, but adds besides, Fucus comosus of Labillai-diere, and Fucus
Sysimbrioides and Horneri, of Turner.
1. H a l id r y s s il iq u o s a . Tab. I.
Halidrys siliquosa, L y n g b . H y d r o p h . D a n . p . 37.
Cystoseira siliquosa, A g . S p . A lg . v . 1. p . 72. S y s t . A lg . p . 287- S p r e n g . S p . P L v . 4.
p . 317- G r e v . F I . E d in . p . 285.
Fucus siliquosus, L in n . S p . P I . p . 1829. S to c k h . N e r . B r i t . t. 5. T u r n . .Syn. p . 60.
H i s t . F u c . t . 169. L am o u r . E s s a i, p . 17. S m . E n g . B o t. t . 474.
Var. a minor, F u c u s s illc u lo s u s , S t a c k h . N e r . B r i t . t . I I .
H a b . in the sea. Var. ¡3 in rocky basins and pools exposed by the
tide. Perennial. Common on almost every part of the British coast.
Root a hard conical disk. Frond one to four feet long, linear,
flexuose, compressed, mostly undivided, pinnated irregularly with
spreading branches of various lengths, in a distichous manner :'the
branches rarely again divided, but set, as well as the main stem, at