“ On the edges of ditches, and in similar situations, it
frequently occurs in masses so densely matted, as to hold
water like a sponge, with its surface beset by erect branches,
which give it a very bristly appearance. In this state it is
well known to botanists as the C. amphibia of all modern
authors. Its hue is a bright green, becoming ash-coloured
Avith age. The root I have not been able to discover, and
the entangled mode of its growth renders it impossible to
ascertain the length of the filaments. These are repeatedly
divided with distinct patent branches, which, as before
mentioned, when the plant grows in shallow water, so that
some of them are exposed to the air, send out patent ramuli
of a stunted growth, from being out of their proper element,
wdiich by their erectness give the plant its bristly appearance;
yet, at the same time, if whilst in this state the waters rise
so as to overfloAV the plant, their length is gradually increased,
and losing their erect position, they yield to the current,
and become the Ceramium ccespitosum of Roth ; and after
having thus changed, if by the subsidence of the waters the
surface is again exposed to the air, the filaments, of course
disposed horizontally, give the plant a bristly appearance by
again throwing out erect patent ramuli.”— Dillw.
The above description of Mr. Dillwyn, is applicable, I
suspect, not merely to Vaucheria ovoidea, but to, perhaps,
nearly all the Vaucheria which dwell in shallow water. V.
ovoidea delights, according to Vaucher, in the purest water,
tha t of fountains for example ; and it is certainly not so
common as might be supposed to be, if it were the only
species of the genus which assumed a csespitose character ;
for out of the many hundred examples which I have examined,
I have never yet been so fortunate as to procure the plant in
seed. On the young, dense, and spongy tufts it is rare to
find capsules of any kind.
M. Deeaisne describes movements of the capsular body of
this species altogether analogous to those of V. clavata, detailed
in the Introduction.
f. Capsules numerous, lateral, on separate peduncles.
12. V aucheria poltsperma Hass.
Plate V I. Fig. 6.
Char. Frond minute. Capsules separate, in the form o f
a bird’s head, pedunculated, varying in number from
three to five, but usually there are but three sporangia,
not entirely filling the cavity o f the seed-vessels or capsules.
Hassall, in Annals of Nat. Hist. vol. xi. p. 429.
Hab. Vicinity of Cheshunt.
This species, which is hy no means uncommon, may be distinguished
from all others known to me by the fineness of
its filaments, which are not half so large as those of our other
British species, no less than by the form and arrangement of
the seed vessels. These are slightly pedunculate, varying in
number from three to five, but usually there are but three,
the apices or beaks of which are neither turned towards or
averted from each other, but are all directed one way. The
resemblance which the capsules bear to a bird’s head when
viewed sideways is very remarkable, and this resemblance is
rendered still more striking by the fact of the circular sporangium
occupying only the central portion of each, and which
therefore represents the eye of the bird.
I t is remarkable to observe th a t in this Vaucheria there
are no distinct horns or antheræ, the base of each vesicle
before its complete formation appearing to represent the
anther.
g. Proper Capsules none, Antheræ none.
13. V aucheria clavata Vauch.
Plate I I .
Char. Frond coespitose, the extremities o f the branches
clavate.