Volume 9 - Electric Scotland

NEW AND RARE SCOTTISH MOSSES 179
or broadly ovate rather suddenly, and longly as well as slenderly
acuminate ; margin plane or, in the specimen from Ben Lawers,
narrowly recurved at times near the base, serrulate for the most
part nearly throughout, occasionally nearly entire; nerve slender,
at times bifurcate, reaching the middle of the leaf or a little longer.
This moss is much larger in every way than /. myosuroides, of a
much larger habit, with larger leaves, equalling or even exceeding
those of /. myierum, although of quite a different shape. It has also
been found in Orkney.
There is still another moss approaching more nearly /. myosuroides
than the above, with narrower leaves, which are, however, rather
suddenly and longly acuminate, and not narrowing towards a point
in a straight line as in /. myosuroides. To this I gave the name
/. subglaciale.
The following is
supplementary to the description given in
1865:
Stems slender, long and straggling, procumbent, yellow, then
reddish, irregularly and distantly, but here and there, fasciculatoramose,
branches straight or slightly incurved ;
stem leaves smaller,
scattered, spreading, broadly ovate lanceolate, longly acuminate,
nearly entire, margin plane, nerves short, at times apparently
double ;
branch leaves narrower, ovate lanceolate, also acuminate,
nerved half way, serrulate nearly throughout. Areolation as in /. interludens,
viz. general areolation 25 to 40 by 4 to 5, separate and
distinct. Slender flagelliform shoots, with small scattered leaves,
are frequently seen. No fruit has ever been found on either moss.
ISOTHECIUM SYMMICTUM. In depressed or ascending, yellowishgreen
tufts, here and there stoloniferous ;
stems nearly simple or
fastigiately branched, branches mostly simple, often slightly curved ;
leaves crowded or even imbricated when dry, slightly spreading
when moist, concave, broadly ovate, rather longly acuminate, margin
plane, often slightly incurved above, serrulate in upper third, at
times nearly entire, striate or even sulcate, nerve yellow, at length
orange-red, stout near base, rapidly tapering and reaching beyond
the middle ;
bases of leaves composed of two or three transverve
rows of reddish-brown oval cells, 1 6 to 22 by 8 to 12, which extend
right across with scarcely any alar cells, properly so called ; general
areolation long, fusiform, sharply pointed, attached, 55 to So by 4.5
to 6. The cells immediately above the coloured base are shorter
than the others above them, and somewhat oval or bluntly fusiform.
Ben Lawers, 1864. The areolation of the leaf differs widely from
that of the other species of Isothedum, and resembles that of some
Brachytheria, but the basal areolation and the presence of stolons
determined in favour of association with Isothedttm, while the
fastigiate branching, and the slightly curved branches themselves,
strengthen this opinion.