IT ^
O j:!
site to the ramuli; and the very short processes which sometimes occur
in a similar situation are rather, perhaps, to be considered abortive
capsules, than imperfect ramuli. The whole frond is made up of a
delicate cellular tissue.
G e n u s X X X II. LAURENCIA, Lamour. Tab. XIV.
G e n . Ch a r . Frond cylindrica], filiform, between cartilaginous
and gelatinous, mostly yellowish or purplish red.
Fructification of two kinds: 1. ovate capsules, with a
terminal pore, containing a cluster of stalked pear-
shaped seeds, fixed by their base; 2. ternate granules
imbedded in the ramuli.
O bs. The name bestowed upon this genus by Lamouroux is designed
to commemorate a friend of the name of De Lalaurencie, who
was very partial to pursuits of natural history.
Agardh, however, brought together tbe Laurencioe and a number of
other species, in order to form his genus Chondria, but they differ
much in habit, and so much in fructification, that the generic character
does not in reality affect half of them.' Even as it is, the fructification
is only known of Laurencia Forsteri, obtusa, pinnatifida, dasyphylla,
and tenuissima ; but the habit of the remainder, viz. L. laxa, papil-
losa, botryoides, seticulosa, and fasciculata, is so striking, that a doubt
can hai'dly be admitted of their fructification being similar. All the
species have their branches either obtuse and often lobed, or set with
little incrassated ramuli ; and it is in these parts that the ternate granules
are always imbedded. The root is scutate, but generally throws
out a few creeping fibres.
* Ramuli turgid, obtuse.
1. L a u r e n c i a p in n a t i f id a . Tab. XIV.
Frond compressed cartilaginous twice or thrice pinnatifid branches
alternate the pinnulæ erecto-patent obtuse simple or lobed.
Laurencia pinnatifida, L am o u r . E s s a i, p . 42.
’ Chondria pinnatifida, A g . S p . A lg . v . 1. p . 337- S y s t. A lg . p . 201. ' G r e v . F I . E d in . p . 291.
S p r e n g . S p . P I . v . 4. p . 341.
Gelidium pinnatifidum, L y n g b . H y d r o p h . D a n . p . 40. t . 9.
Fucus pinnatifidus, H u d s . F I . A n g . p . 581. S t a c k h . N e r . B r i t . ç . 4 8 . 1 . 11. T u r n . S y n .
F u c . p . 267. H i s t . F u c . t . 20. S m . E n g . B o t. 1. 1202.
V a r . Osmunda, f r o n d f la t , g e n e r a lly u n d iv id e d ; r a m u l i s h o r t a n d m u l t i f id . T u r n .
Fucus Osmunda, G m e l. H i s t . F u c . p . 1 5 5 . 1 . 16. f . 2. S t a c k h . N e r . B r i t . p . 46. t . 11.
V a r . y angusta. F r o n d ro u n d i s h , r a m u l i c y lin d r ic a l, th ic k e n e d u p w a r d s , s e t o n a l l s id e s
o f t h e s t em , o f te n c lu s te r e d , a n d s im p le . T u m .
Chondria hybrida, C h a u v in , A lg . N o rm . F a s c . 2. N o . 40. a c c o rd in g to a s p e c im e n s e n t.
V a r . ^ tenuissimus. F r o n d f l a t , r a m u l i v e r y t h i n a rid m u c h b r a n c h e d , t h e b r a n c h e s d i v
a r i c a t e d . T u m .
H a b . Rocks in the sea. Annual. June to September. Extremely
common. Var. 5 is found in Devonshire and Cornwall, Mrs Griffiths-
Mr Stackhouse.
Root a fiattish disk, throwing out a few creeping fibres. Fronds
tufted or several from the same base, one to fourteen inches in length,
one to eight inches in entire breadth, more or less compressed, the main
stem divided once or twice in a dichotomous manner, generally a line
or more in width, and insensibly dilated towards the extremity, twice
or thrice pinnatifid, tlie pinnæ and pinnulæ spreading, arising at short
but unequal intervals, dilated, rounded and thickened at the ends,
where they are also sometimes lobed, or set with what appear to be
the rudiments of fresh branches.
The variety /3 is a beautiful plant, the main stem widening upwards
till it is half an inch in breadth, and then again decreasing towards the
extremity, the margin being only fringed with short obtuse many-cleft
ramuli.
The variety y is chiefly characterized by cylindrical branchlets,
which at the same time are frequently inserted on all sides of the stem
or branches. It varies much in size (from one to five inches in length)
and in tbe degree of ramification. Sometimes the stem is only set on
its upper half with clustered simple incrassated branches : sometimes,
on the other hand, there are three or four series of branches ; but even
in that case, the secondary branches are mostly naked on their lower
half, and bear the ramuli in a thick sort of spike, or rather in the form
of a thyrsis. This variety is often of a fine green colour, not only
when dried, but even when growing.
The variety S is chiefly conspicuous for the branches being two or
three times narrower than the stem, and for the divarication of the
ramuli.
Fructification ; 1. broadly ovate capsules situate towards the extremity
of the ramuli, about the size of poppy-seed, containing red pear-
shaped seeds supported on narrow stalks; 2. ternate granules imheA-
ded in the ramuli.