Maslova, E.V., Yu.V.
Mosseichik, I.A. Ignatiev
& M.S. Ignatov. Bulbosphagnum, a new
form genus for vegetative propagules of the
Palaeozoic order Protosphagnales
Arctoa (2016) 25: 314–331
doi: 10.15298/arctoa.25.25
Spheric to ovoid
or bulb-like brood bodies are
found in Upper Palaeozoic mosses of the
order Protosphagnales. They developed on stems and
leaf costae, and putatively also on the
apical parts of leaves. Their
surface was smooth or, more
commonly, rough due to short
rhizoid initials densely covering their surface all
around. It seems that rhizoids
developed especially after brood bodies
started growth, becoming larger and then forming
stem. Rhizoids on brood bodies
and on stems
growing out of them have
oblique cell walls, characteristic to all other
mosses. They definitely belong to species of
Protosphagnales, wherefrom they were not
reported earlier. However, as the
taxonomy of the genera of
protosphagnalean mosses is based primarily
on leaf characters,
a new form-genus
Bulbosphagnum is
described to accommodate numerous brood bodies themselves
and also brood bodies with
leafless stem bases. In the
extant flora, the most similar
brood bodies are known in
Oedipodium where they also may
form on various
parts of plants and have
similar shape and size, although
differ in fewer rhizoid production
as compared with Bulbosphagnum.