6.
Weissia brachycarpa
(Nees & Hornschuch) Juratzka, Laubm.-Fl. Oesterr.-Ung. 9. 1882.
Hymenostomum brachycarpum
Nees & Hornschuch in C. G. D. Nees et al., Bryol. Germ. 1: 196, plate 12, fig. 3. 1823;
H. microstomum
(Hedwig) R. Brown;
H. microstomum
var.
brachycarpum
(Nees & Hornschuch) Huebener
Leaves
lanceolate to long-lanceolate, base weakly differ-entiated to elliptic, shoulders weak or absent, distal laminal margins very broadly incurved to erect, apex broadly channeled, acute, mucro usually very strong, of 5-7(-10) cells; costal adaxial stereid band smaller than the abaxial; distal laminal cells 8-12 µm wide.
Sexual condition
cladautoicous.
Seta
elongate, (0.2-)0.28-0.4 cm.
Capsule
stegocarpic, ovoid, often slightly curved or bulging on one side, operculum differentiated, falling, peristome absent.
Capsules mature spring. Soil, limestone rocks, grassy areas; moderate elevations; B.C., N.S., Ont.; Ind., Mass., N.J., N.Y., N.C., Ohio, Tex.; Eurasia; n Africa.
Weissia brachycarpa
is a new name for the illegitimate combination
Weissia microstoma
(Hedwig) Müller Hal.
Weissia brachycarpa
is easily distinguishable from related
Weissia
by the mostly plane (not tightly inrolled) distal leaf margins and usually a rather large mucro, composed of ca. 10 clear cells, but often only of 4-6 cells; other
Weissia
species have mucros of about six cells. Often the distal margins are sharply incurved (a sharp inflexion seen in section) and although the gametophyte has the appearance otherwise of
Trichostomum crispulum
, the largely plane (or broadly incurved) distal margins may be taken as a secondary character, perhaps a reduction.
Weissia ludoviciana
, likewise, has largely plane distal leaf margins, but inflexion may be evident in some specimens. In addition, the very long and narrow leaves of
W. brachycarpa
and
W. ludoviciana
are not duplicated in
Trichostomum
except in the
T. tenuirostre
complex.
Weissia brachycarpa
is cladautoicous, with perigonial buds borne in the axils of lower branches of robust fruiting plants.
Weissia brachycarpa
is related to
W. rutilans
of the Old World by the nearly identical gametophytes; the latter species differs in the rudimentary peristome teeth, and slightly larger spores. The nomenclature of
W. brachycarpa
is intricate; see discussions by M. O. Hill (1981) and T. J. Koponen et al. (1977).