■ ! 'I
The name comes from pilula, signifying a little pill, the
spore-cases having a nearly globnlar form.
P il u l a r ia g lo b u l ife r a , Linnæus.— The Pillwort, or
Pepper-grass. (Plate XA^II. fig. 2.)
Pepper-grass is a small creeping plant with grassy leaves,
growing usually in the shallow margins of lakes and pools,
where it is occasionally overflowed ; but sometimes occurring
entirely submerged. The stem, or caudex, is thread-like,
composed of several longitudinal rows of hollow cells, rough
externally on the younger portions with, hair-like scales, hut
otherwise smooth, occasionally branched, and producing on
the lower side at intervals of about half an inch, less or
more, small tufts, of fibrous roots, which are slender, simple
or slightly branched, hollow, being divided longitudinally,
and descending almost perpendicularly into the soil in which
they become fixed. On the upper part of the stem, opposite
the tufts of roots, occur tufts of about a similar number of
erect leaves, which are curled up in the incipient state, like
those of a Pern, but on unrolling assume the erect position.
These leaves are bristle-shaped, and of a bright green,
smooth externally, hollow within, but unlike those of Lsoetes,
which are composed of four paraUel lines of cells, the leaves
of the Pillwort are divided longitudinally into various cells.
separated by partitions radiating from the centre; they are
from one to four inches long.
The fructifications consist of small globular spore-cases,
attached by a very short stalk to the stem at the points
whence the leaves and roots proceed, being in fact seated at
the base, or in the axils of the leaves. They are densely
covered externally with pale brown jointed hairs, and are
about the size of a small pea or pepper-corn. These spore-
cases are typically four-celled, and when quite mature, open
at the apex, and divide into quarters, the four parts remaining
attached to the footstalk by their base. The spores
are attached to the interior of these valves along their centre,
forming four lines, the lower part of the spore-case being
occupied by the large, and the upper part by the small
powdery bodies already mentioned; the former are of a
greyish colour, and have a roundish-oblong form, with a contraction
in the middle, and a terminal nipple-like point, the
latter consist of oblong' pale yellow bodies filled with a
powdery matter resembling pollen; both are contained in
transparent gelatinous bags.
The larger spores have been regarded as pistils, and the
smaller ones as anthers, by those who have maintained the
sexuality of these plants; but there is no evidence whatever