That Dicranum polycarpum of H e d w ig is a species even
now not satisfactorily understood, is a fact which few bryologists
I believe will be inclined to deny. Nor is it improbable that
a portion of the uncertainty which seems to have attached to it,
may have arisen from the subject of the present description
having been from time to time confounded with it, especially
in this country, where it has been thus taken up by the authors
of the Museologia Britannica. M. K a u l e u s s , a successful
investigator of Bryology, discovered the present moss near Cilley
in Styria in 1812, as we learn from his own account in S t u r m ’s
Deutschlands Flora.” He described it as a Didymodon,
but does not appear to have seen a perfect peristome, for he
both describes and figures the teeth as remarkably short, and
of a lanceolate form. S c h w a e g r ic h e n , who has also described
and given a figure of it in the first part of his second
Supplement, from specimens communicated by K a u l e u s s , has
not fm-nished any additional representation, since he borrows
K a Ul f u s s ’s own figure of the teeth.
My excellent correspondent Dr M o u g e o t , who was kind
enough to send me perfect rspeeimens very recently, seems to
have been the first to ascertain the true nature of the peristome,
and observes to me in a letter, that the teeth are in
reality»very different from the figures puhlished'of them. In
fact, they are long, and though broad at the base, soon become
very slender, and generally more or less contracted at the
joints formed by the transverse striae. They are very fragile,
and scarcely to be seen entire, without carefully removing various
opercula.
In general habit, D. obscurus closely resembles Weissia
cirrata, but often grows to a larger size than that moss.
Figs. ], 1. D. obscurus, nat. size. Fig. 2. Cauline leaves. Fig. S . Summit o f
a cauline leaf. Fig. 4. Perichaitial leaf. Fig. 5. Capsule with Calyptra-
Fig. 6. Capsule, with the lid. Fig. 7. Part c f the capsule, with the peristome.
Fig. 8. Three pairs o f teeth removed from the peristome. Fig. 9.
Sporules, magnifed.