THE GENUS BRYUM (BRYACEAE, MUSCI) IN MIDDLE ... - Arctoa

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The study area includes Middle European Russia
(i.e., European Russia, excluding the Caucasus
and northern territories: the Kola Peninsula, Karelia,
Northern half of Leningrad/St.-Petersburg
Province, and northern Arkhangelsk Province and
the Komi Republic, and including the Ural Mountains
up to the northern border of Perm and
Sverdlovsk/Ekaterinburg Provinces).
All Bryum collections from the study area in
MW, MHA, LE and VOR have been examined, as
well as some from H and local Russian herbaria,
including Tver State University, Ekaterinburg Pedagogical
University, Institute of Ecology (Ekaterinburg),
and Volgograd Pedagogical University.
Altogether, approximately 700 specimens were
studied. Several species cited in publications pertaining
to Middle European Russia were not available
for study, and these are cited in the section
“unconfirmed records”.
Measurements in species descriptions are based
on ten specimens from different parts of the territory,
if this number was available. The number of
specimens studied is indicated in parentheses after
“specimens studied”. Species known only from
sterile plants are supplemented with descriptions
of sporophytes (and sometimes perigonia and
perichaetia) based on other, mostly European collections,
which are listed in Appendix 1. All data
from outside of our area are in square brackets.
The SEM analyses of peristome and spores include
several species from outside of the study
area, and a number of these are used to illustrate
particular character states.
ANALYSES OF CHARACTER STATES
Sexual condition traditionally has been considered
one of the important characters in Bryum
taxonomy, because most species are invariable
in this respect. In some groups, the differences
in sexual condition were treated as an important
basis for species segregation, e.g., with
Bryum pseudotriquetrum–B. bimum, B. pallescens–B.
lonchocaulon–B.creberrimum, and B.
capillare–B. torquescens. However, recent authors
have expressed doubts about the significance
of this character, which (along with other
evidence) has led some to reduce the status
of B. bimum to a variety or a synonym with B.
pseudotriquetrum, and to treat B. lonchocaulon
(as B. cirrhatum) as synonymous with B.
pallescens. Sexual condition was found, in the
present study, to be fairly stable. The most puz-
V. I. ZOLOTOV
zling case is the group, B. pallescens–B. lonchocaulon–B.
creberrimum; it is discussed in
detail under the first species.
Male and female plants of dioicous species are
often in separate tufts, but in some species both
sexes can be often found in the same tuft (for
example, in B. pseudotriquetrum), at least if the
collection is large. Male plants are usually slender,
more loosely foliate (B. pallens, B. caespiticium),
or almost identical with female plants (B.
schleicheri). Perigonia are usually about as long
as wide, and have a + capitate shape, but in some
species (B. schleicheri, B. pseudotriquetum) with
especially numerous antheridia, perigonia are wide,
i.e., noticeably wider than long.
Plants grow as separate individuals scattered
on the substrate (often in B. funkii, sometimes
in B. argenteum), or form loose (B. weigelii),
compact (B. bimum), or dense tufts (B. caespiticium).
I call a tuft ‘compact’ if a complete shoot
can be pulled off the tuft from above, whether
dry or wet. Correspondingly, I call a tuft ‘dense’
if a shoot usually breaks in attempts to pull it
from above, and the separation of a single shoot
requires first a splitting of a tuft and then the
careful removal of a plant from the opening. The
compact or dense states are generally dependent
on the density of rhizoidal tomentum, but they
are not correlated in all cases. Therefore, tuft
density can be treated as a separate character.
The height of tufts is a complex parameter resulting
from the length of female shoots, the length
of subterminal shoots, and the mode of growth
(shoots are mostly straight, or sometimes ascendant,
as in B. rubens, B. laevifilum, or shady phenotypes
of B. capillare, and includes both living
and dead, partly decayed parts). Tufts vary from
low (less than 0.5 mm, as in B. violaceum) to tall
(10-12 cm, as in B. pseudotriquetrum, B. schleicheri,
B. weigelii).
Tuft color can be pure green (B. capillare),
light green (B. rubens), dirty green (often in B.
turbinatum), pale green (often in B. weigelii), yellow-green
(B.cirrhatum), brownish-green (sometimes
in B. bimum), brownish-yellow (sometimes
in B. elegans), pinkish to vine-red (often in B.
pallens), glaucous (sometimes in B. laevifilum and
B. turbinatum), whitish (B. funkii), silvery (B.
argenteum), or variegated with a mixture of green,
yellow-brownish and purplish (B. alpinum). Tufts
can be dull (B. weigelii) or glossy (B. alpinum).