[ 1582 ]
GYMNOSTOMUM Donnianum.
Donnian Beardless-moss.
&
CRYPTOGAM1A Musci.
G en . Char. Caps, without a fringe. L id deciduous.
Veil separating entire from the base.
Spec. Char. Stem none. Leaves bristle-shaped.
Capsule turbinate, smooth. Lid oblique, the length
o f the capsule.
F o r the knowledge of this, one of the minutest of mosses,
we are entirely obliged to Mr. G. Donn of Edinburgh, who
first observed it in 177 9, when he was a very young botanist,
clothing the surface of a rock in the Den of Dupplin, Perthshire.
He has repeatedly visited it in its native situation since,
and found it in other parts of the same valley, but not in
fructification. The season for the capsules is November, and
the root is probably annual.
No stem is discernible. The leaves grow in either one or
more clusters, nearly erect, bristle-shaped, beardless, sheathing
one another at their base, of a full rich opaque green.
Fruitstalk solitary, upright, capillary, yellowish, about a line
high. Capsule erect, turbinate or topshaped, very minute,
yellowish, opaque, quite smooth as if neatly turned out of box
wood, tapering at the base, wide at the mouth, with the little
column projecting in the centre as in several species of Splach-
mem. Fringe certainly none. Lid tapering, according to
Mr. Donn, oblique, as long as the capsule.
The bristle-shaped leaves and long lid distinguish it from
G. Davallianum, mentioned by Mr. Drake in the Annals of
Botany, v. 1 . 577* while the smooth and rounder capsule
keeps it quite separate from G. trichodes of Mohr. It is indeed
smaller than either of those species, and scarcely half the size
of Grimmia pusilla, which at first sight it otherwise greatly
resembles.