m
112
* * liainuH muck attenuated at their hase.
3. L a u r e n c ia d a s y p h y l l a .
Frond cylindrical irregularly branched ultimate branchlets very
short subtruncate much attenuated at their insertion.
Laurencia cæspitosa, L am o u r . E s s a i, p . 43.
Chondria dasyphylla, Ag . S p . A lg . v . 1. p . 350. S y s t . A lg . p . 205. S p r e n g . S p . P I . v . 4.
p . 342.
Gigartina dasyphylla, L am o u r . E s s a i p . 48.
Fucus dasyphyllus, W o o dw . in L in n . T r a n s , v . 2. p . 239. t. 21. T u m . S y n . FUc. p . 38.
H i s t . F u c . t . 22. Sm . E n g . B o t. t . 847-
H a b . In the sea, attached to rocks and stones. Annual. June to
September. Yarmouth, Mr Wigg. Cromer, Mr Woodward. Sheringham,
Mr Turner. Coast of Dorsetshire, Mr Bryer. Cornwall,
Mr Stackhouse. Torquay and Sidmouth, Mrs Griffiths. Dawlish,
Mr Pigott. Rocks at the Mumbles, near Swansea, and at Dover,
Dillwyn. Beach at Corton, and Gunton, Suffolk, Mrs Fowler. Near
Belfast, Dr Drummond. Lossiemouth, in Scotland, Mr Brodie- Isle
of Bute.
Root a minute disk, throwing out a few creeping fibres. Fronds
several from the same base, generally rising with a main undivided
stem, three to twelve inches in height, cylindrical, filiform, half a line
to a line in diameter, branched from within a short distance of the
base : hranches nearly horizontal, sometimes few and remote, sometimes
very numerous and even bushy, arising without order, and bearing
a second and even third series, the last always becoming gi-a-
dnally shorter towards the ends of the branches, where they are less
than a line in length, and almost top-shaped. The whole frond in
many specimens is marked with regular transverse striæ. Fructification
; 1. ovate sessile capsules on the younger branches, containing
stalked pear-shaped seeds ; 2. ternate granules in the ultimate ramuli.
Substance rather gelatinous than cartilaginous ; adhering to paper in
drying. Colour a pale reddish pink, becoming darker when dried,
very fugitive, and changing in decay to a yellowish or dirty brownish
white.
All the specimens that have hitherto come under my observation
have exhibited the transverse striæ more or less distinctly. Their
breadth is much greater than their length. Upon a careful dissection
of the internal structure, it does not appear that these striæ are pro-
Laurencia.] F L O R ID EÆ . 1 1 3
duced by real septa or paititlons, but by a similar arrangement of the
cellules to what is observed in Rhodomela pinastroides. Mr Turner,
however, mentions that some specimens are without striae, and Agardh
considers the striated ones as forming a distinct variety. The subject
deserves farther investisration.
5i::
. f '
4. L a i ; r e n c ia t e n u is s im a .
Frond cylindrical irregularly branched ultimate branchlets setaceous
much attenuated at their base.
Gigartina tenuissima, L am o u r . E s s a i, p. 48.
Chondria tenuissima, Ag . S p . A lg . v . 1. p . 352. Sy.st. A lg . p . 205. S p r e n g . S p . P L
V. 4. p . 340.
Fucus tenuissimus, G o o d e n , a n d W o o dw . in L in n . T r a n s v . 3. p . 215. t. 19. T u r n . S y n .
F u c . p . 35. H i s t . F u c . t . 100. S m . E n g . B o t. t. 1882.
H a b . In the sea, on rocks and stones and the larger Algse. Annual.
July to September. Near Weymouth, under the “ Look-out,” Good-
enough and Woodward. Isle of Wight, Rev. G. R. Leathes. Near
Torquay, Mrs Griffiths. Cornwall, English Botany.
Root a minute disk, throwing out creeping fibres. Fronds several
from the same base, six to nine inches in height, generally arising with
a single cylindrical stem less than a line in diameter, which gives off
numerous long nearly horizontal very slender branches, terminating in
almost bristle-like points; the branches are set with a smaller series,
and all of them bear a number of minute bristle-like ramuli one or two
lines in length, and tapering very considerably at their base. Fructification:
1. ovate sessile capsules, containing stalked pyriform seeds,
situate on the younger branches and setaceous ramuli; 2. ternate granules
imbedded in the setaceous ramuli.
Substance very tender, hetween cartilaginous and gelatinous, adhering
to paper, and shrinking in drying. Colour a pale pinky red.
The form of the ultimate ramuli give as peculiar an appearance to
this species as to the preceding one. There is no danger of their ever
being confused.
Laurencia tenuissima must be accounted one of our rarest Algce,
being confined to the south-western coasts of the island, and nowhere
very plentiful.
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