f J. byssaceaj 
BRITISH JUNGERMANNIjE. 
the segments are acute, occasionally a little spreading, which induced Dr. Smith to 
adopt, in English Botany, Mr. Francis’ manuscript name of divaricata. The color of the 
leaves corresponds with that of the stem, and is equally subject to vary from a 
dark ( for I have seldom seen it of a pale ) green to a deep brown : when dry the 
leaves are rigid and brittle. The reticulation is small, formed by subquadrate 
cellules. 
Perichcetial leaves ( f. 5. 5 ) numerous, surrounding the base of the calyx, and closely 
imbricated, subquadrate, approaching to round; the exterior ones for the most part 
divided by an obtuse sinus into two equal, acute, erect segments ; the interior cut 
into three, four, or five unequal ones : they are all of a paler color than the rest of 
the leaves, but resemble them in the size and form of the cellules of which they 
are composed. 
Male fructification, according to Dr. Smith, within the axillae of the terminal tufts of 
leaves. Anthers small, spherical, yellow, situated upon short, pellucid footstalks. 
Female fructification always terminal upon the stems and branches. 
Calyx (f. 6) large in proportion to the size of the plant; about a quarter of a line long, 
oblong, plicate : the mouth, which is by no means contracted, is cut into small obtuse 
teeth. The whole is extremely delicate, appearing like a thin membrane, though under 
a high power of the microscope the reticulation formed by oblong cellules is very 
apparent. At the base the calyx has generally a faint tinge of green; the extremity 
is white, and diaphanous. 
The calyptra is ovate, extremely delicate and pellucid. 
Peduncle remarkably slender, a line or a line and a quarter long, white, cellulose, 
shining. 
Capsule (f. 7) oblongo-ovate, deep red-brown, longitudinally and transversely furrowed. 
Seeds and spiral filaments (f. 8) of a reddish-brown, the former perfectly spherical, the 
latter composed of a double helix. 
Obs. The nearly capillary surculi, in consequence of the minuteness of the leaves, which 
are scarcely to be distinguished by the naked eye, are compared by Dr. Roth to Byssus velutina; 
whence his specific name. 
That the present plant is the J. byssacea of Roth I believe there will be found no reason to 
doubt. Authentic specimens in Dr. Smith’s herbarium exactly correspond, and the description in 
the Flora Germanica is excellent. This author justly observes that “ siccitate caules ob folia 
remota contracta quasi nodulosi, et primo intuitu Corallince officinalis ramulum repraesentant. 
I cannot, however, coincide with him in considering it a variety of, nor in supposing it has any 
kind of affinity with, Hoffmann’s J. excisa, which, to judge both from the description and remark 
at the end of it, is the same species as Mr. Dickson’s plant, of the same name. Dr. Roth farther 
