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Arctoa (2007) 16: 87-98
ON THE REPRODUCTIVE BIOLOGY OF PTILIUM CRISTA-CASTRENSIS
(PYLAISIACEAE, BRYOPHYTA)
К РЕПРОДУКТИВНОЙ БИОЛОГИИ PTILIUM CRISTA-CASTRENSIS
(PYLAISIACEAE, BRYOPHYTA)
VIKTORIA V. TELEGANOVA1,2 & MICHAEL S. IGNATOV2
ВИКТОРИЯ В.ТЕЛЕГАНОВА1,2, МИХАИЛ С. ИГНАТОВ2
Abstract
Ptilium crista-castrensis – dioicous pleurocarpous moss with ascendent to erect
stem; mature gametangia are situated on parts of shoots of the second year, and sporo-
phytes occur on parts of shoots of the third year. Female gametangia-bearing plants
are 20% larger on average than male gametangia-bearing plants, while sterile plants
of both genders do not differ in size from each others. At the same time, the percent
of sterile plants within male populations is smaller than in female populations. In
most parts of Russia the proportion of male and female collections in herbaria is
close to equal; however, in the severe climate of Arctic and Yakutia, male plants are
very rare and female plants prevail.
Резюме
Ptilium crista-castrensis – двудомный бокоплодный вид с восходящим до
прямостоячего ростом, у которого развитые гаметангии располагаются на участках
побегов второго года, развитые спорофиты – на участках побегов третьего года.
Показано, что женские растения в среднем на 20% крупнее мужских, но в то же
время стерильные мужские и женские растения сходны по размерам, то есть
женские генеративные отличаются от женских стерильных сильнее, чем мужские
генеративные от мужских стерильных. При этом процент стерильных мужских
растений в мужских популяциях значительно ниже, чем процент стерильных
женских в популяциях женских растений. В большинстве районов России
соотношение полов примерно равное, однако в наиболее суровых условиях
Арктики и Якутии количество мужских растений резко сокращается.
1 – National Park “Ugra”, Prigorodnoe lesnichestvo, Kaluga 248007 Russia – Россия 248007 Калуга, пос.
Пригородное лесничество, Национальный парк “Угра”; teleganovavika05@rambler.ru
2 – Main Botanical Garden of Russian Academy of Sciences, Botanicheskaya, 4, Moscow 127276 Russia –
Россия 27276 Москва, Ботаническая, 4, Главный ботанический сад РАН; misha_ignatov@list.ru
INTRODUCTION
About half of the mosses are dioicous (Long-
ton & Schuster, 1983; Wyatt, 1982), but the de-
scription of sexual dimorphism is a subject that
remains almost unexplored in mosses. In acrocar-
pous mosses with terminal gametangia, the ap-
pearance of male and female plants is often obvi-
ously different, as their perigonia and perichaetia
contribute much to plant habit. Perigonial leaves
are in general shorter and more shortly acute or
acuminate comparatively with perichaetial leaves,
thus male and female plants of many Bryum, Di-
cranella, Polytrichum, etc. can be easily recog-
nized by their habit in the field. At the same time,
perigonia and perichaetia in pleurocarpous moss-
es are lateral and usually quite inconspicuous, es-
pecially in plants with relatively large leaves. The
difference between male and female plants of pleu-
rocarpous taxa probably was never a subject of
special studies, as they are thought to be identical
in structural and dimensional vegetative charac-
ters. At least taxonomic treatments never include
separate descriptions of male and female plants
unless the male is a dwarf male.
88 VIKTORIA V. TELEGANOVA & MICHAEL S. IGNATOV
Sex distribution in pleurocarpous mosses was
recently the subject of an overview of Bisang &
Hedenäs (2005) who demonstrated that various
ways of evaluation reveal the female bias in most
mosses. They did not include in their paper Ptili-
um crista-castrensis (Hedw.) De Not. because of
lack of data. This moss attracted our attention be-
cause of a relative ease of sex determination in
the field and also because a preliminary study re-
vealed that many populations in Moscow Prov-
ince have strong male bias.
Ptilium crista-castrensis is a widespread moss
of boreal forests, occurring on litter or rotten logs
at late stages of decomposition. It is known in most
regions of Russia, excepting the most xeric ones.
Ptilium crista-castrensis is a dioicous pleuro-
carp classified in Hypnaceae (Goffinet & Buck,
2004) or Pylaisiaceae (Ignatov & Ignatova, 2004).
Plants are rather robust, stems densely regularly
pinnate in one plane, ascending to erect, usually
inclined making 45-85° with soil surface; this an-
gle, as well as secund leaves, makes unequivocal
the understanding of the upper and lower surfac-
es of the stem. Gametangia are restricted to stems;
perigonia are always situated on the lower-lateral
surfaces of stems and faced downward, whereas
perichaetia develop on lateral or even low-lateral
surfaces of stems, but in both cases turn to an up-
right position (Fig. 1). This distinctive appearance
makes the gender determination easy in the field
with just a hand lens (or sometimes even by na-
ked eye when mature perigonia are colored and
conspicuous on the lower surface of stems).
MATERIAL AND METHODS
Three approaches were used in the present study:
(1) ‘large-samples study’; (2) study of herbarium
collections, and (3) gender mapping in plots.
Large-samples study
In 2006 we studied a number of rather large
samples gathered in European Russia (Moscow,
Kaluga and Vologda Provinces), and Sakhalin in
Russian Far East (Table 1). Altogether 7 male and
8 female samples were studied. Sterile plants from
male populations were considered as sterile males
and, correspondingly, sterile plants from female
populations were considered as sterile females. In
the further discussion we will call “sterile males”
and “sterile females” for these unisexual popula-
tions. 235 male, 151 sterile male, 312 female and
250 sterile female plants were measured during this
large-samples study (see Table 1 for details).
In addition to gender identification, we mea-
sured length of branches (maximal length for giv-
en plant, accuracy 0.5 mm) and determined branch
density (number of branches per 1 cm of stem at
level of longest branch). Branch length was mea-
sured for both gametangia-bearing plants and ster-
ile ones from the same tuft.
Results were analyzed in PAST 1.81 (Hammer
et al., 2008); Mann-Whitney test was used for eval-
uation of differences between genders (α=0.05).
Herbarium study
The spatial distribution of sexes in Ptilium and
its sexual dimorphism were studied also by herbar-
ium materials from MHA, MW, LE, PTZ, PZV.
Altogether 372 specimens with expressed sex from
the territory of Russia were investigated (Table 2).
Herbarium collections were analyzed for the
Fig. 1. Ptilium crista-castrensis: 1-3 – perigonia (from lower side of shoot); 4-6 – perichaetia (from upper side of shoot).
1 2 3 4 5 6
89
On the reproductive biology of Ptilium crista-castrensis
locality N branch length, mm number of branches difference between plants with expres-
mean±ci on 1 cm of stem branch length in fertile sed sex, % of studied
mean±ci and sterile plants, mm plants (n)
fert ster M F M F M F M F n
European Russia 50 50 8.78±0.42 8.74±0.37 0.4 35.37 311
Vologda 55 50 10.47±0.38 10.22±0.26 3.3 11.04 534
60°00’N. 38°30’E 40 50 12.38±0.62 9.05±0.39 3.2 14.49 276
50 30 11.34±0.48 9.53±0.40 3.3 41.91 303
European Russia 20 20 9.86±0.43 9.6±0.58 1.3 19.8 101
Moscow 37 20 10.69±0.40 10.97±0.59 1.9 36.63 146
(Zvenigorod) 30 20 9.12±0.79 9.23±0.43 2.3 69.86 109
55°42’N. 36°43’E 15 20 11.7±0.57 10.6±0.42 4.4 12.88 101
35 14 10.67±0.78 9.49±0.36 2.9 87.16 132
35 20 10.71±0.50 9.4±0.39 3.9 12.57 183
European Russia 35 20 8.1±0.62 10.23±0.39 0.3 85.8 169
Kaluga 30 19 13.32±0.61 10.1±0.47 4.6 30.67 122
53°55’N. 35°45’E 35 20 9.37±0.56 10.13±0.35 1.4 42.11 163
30 21 11.98±0.62 9.5±0.40 3.4 23.81 210
Asian Russia. 30 7 7.43±0.74 10.97±0.56 1.2 94.57 129
Sakhalin 30 20 10.63±0.49 14.55±0.46 2.1 37.04 108
50°45’N. 143°18’E
m/f sm/sf
Total: 235/312 151/250 9.01±0.27 11.35±0.20 9.27±0.15 10.19±0.21 1.40±0.87 3.34±0.70 62.10±27.24 24.56±9.43
Table 1. Data of ‘large-samples study’. Asterisk * indicates bisexual collection where sterile plants were probably of both genders; M–male; F–female. N –
number of plants used for measurements; number of plants used for gender determination is somewhat larger (n, last column); ci – confidence interval of 0.95.
90 VIKTORIA V. T ELEGANOVA & MICHAEL S. IGNATOV
male:female ratio for regions (using subdivision
of Russia from Ignatov, Afonina, Ignatova et al.,
2006). Maximal branch length per collection with
expressed sex was measured in herbarium speci-
mens, but sterile plants were not measured as their
gender was impossible to identify.
Gender mapping in plots
Mixed populations, representing both genders,
were not found in 2006, but they were found several
times in 2007 in Moscow Province, Zvenigirod Bi-
ological Station of Moscow University (50 km W
of Moscow City). Part of one bisexual population
was mapped as follows. The mat was selected in
mossy spruce forest where Ptilium was abundant and
had relatively numerous sporophytes. A portion of a
mat of 85 x 25 cm was taken to a box, photographed
by digital camera, and then each shoot taken from
the mat was related to its digital picture on a com-
puter screen. After gender (or sterile state) was de-
termined, the corresponding shoot was marked in
Adobe Photoshop by dots of four colors: male, fe-
male, sterile, with sporophyte (Fig. 8).
Similar mapping was made also in unisexual
populations 20 x 20 cm (Figs. 5 and 6), in close
proximity to bisexual one. During the counting,
however, within the male population one female
plant and one plant with young sporophyte were
Region M F (c.fr.) mixed (c.fr.)
ARC 1 5 2 (1)
ARC-ESIB 1 5 (1) 0
ARC-FE 1 2 0
ARC-WSIB 4 7 0
ARC-YAK 5 10 0
C 20 21(7) 7 (4)
CAUC 8 6 (1) 0
E-SIB 5 2 5 (4)
NE 5 12 (1) 7 (7)
N-FE 3 2 (1) 0
N-UR 3 2 1 (1)
NW 29 44 (6) 6 (4)
SE 2 0 0
S-FE 10 11 (7) 1 (1)
S-SIB 21 13 (4) 9 (9)
S-UR 16 13 (2) 2 (2)
W-SIB 8 9 (5) 1 (1)
YAK 1 23 (4) 1 (1)
Total 143 187 (39) 42 (35)
Table 2. Herbarium collections of Ptilium from re-
gions of Russia, cf. Fig. 2. M – male, F – female, c.fr. –
with sporophytes (number in parenthesis indicates how
many collections have sporophytes; number before pa-
renthesis – total number of collections). Collections
with sporophytes, but without male plants were referred
to female (cf. however text).
Fig. 2. Regions of Russia, showing (dark) regions where the ratio female:male (by herbarium collections) is
no less than 3:2. See table 1 for exact values.
91
On the reproductive biology of Ptilium crista-castrensis
found. As they constitute less than 0.3% of the
total number of shoots, we will discuss this
mapped plot in Fig. 5 as the male one (not mixed).
The counting of plants of each gender and sterile
ones was undertaken by 5 x 5 cm squares for both
unisexual plots and bisexual plot, thus they were
subdivided into 16 and 85 squares respectively.
RESULTS
Distribution of genders
The count of genders in herbarium collections
is shown in Table 2 and Fig. 2. Female plants slight-
ly prevail, constituting 56.7% of unisexual herbar-
ium collections, if collections of female plants with
sporophytes are counted as female. However, if the
latter collection is counted as a mixed one, then
female plants will constitute 50.9%. Only 11.3%
of the studied collections have plants of both gen-
ders. However, if we consider “mixed collection”
in a broader sense, including female collections with
sporophytes (assuming that male plants grew clos-
er to them), then the number of “mixed collec-
tions” will be much higher, 21.8%.
Interesting (although not unexpected) is the
presence of sporophytes in most of mixed herbar-
ium collections (83.3%), whereas in collection
where only female plants were detected, sporo-
phytes were found much more rarely, in 20.8% of
collections.
Most regions of Russia have a nearly equal ratio
of genders (Table 2), with the indistinct tendency to
male bias to the south (E-SIB is somewhat obscur-
ing this tendency, but there are only few collections
from that area and most of them were from the south-
ern part, close to S-SIB). The tendency to female
bias to the north is quite apparent (Fig. 2), although
these data are rather weakly supported, because in
the Arctic this species is rare, and probably also un-
Fig. 3. Branch length (Y axis, mm) in male (m) and female (f) plants of Ptilium crista-castrensis, including
data on sterile plants from male populations (sm) and sterile plants from female populations (fm). Bars show
confident intervals (see also Table 3).
6
8
10
12
6
8
10
12
6
8
10
12
6
8
10
12
6
8
10
12
SM M SF F SM M SF F SM M SF F SM M SF F
VOLOGDA
SM M SF F
MOSCOW KALUGA SAKHALIN TOTAL
Locality Male Female p
(1) Branch length of fertile plants
Vologda 8.78±0.42, n=50 11.30±0.30, n=145 <0.001
Moscow 9.94±0.46, n=85 10.87±0.39, n=87 <0.001
Kaluga 8.74±0.45, n=70 12.65±0.37, n=60 n.s.
Sakhalin 7.43±0.78, n=30 10.64±0.46, n=39 <0.001
Total 9.01±0.27, n=235 11.35±0.20, n=331 <0.001
(2) Branch length of sterile plants
Vologda 8.40±0.42, n=50 8.13±0.32, n=130 n.s.
Moscow 7.72±0.50, n=54 7.63±0.45, n=60 n.s.
Kaluga 7.93±0.71, n=40 8.64±0.82, n=40 n.s.
Sakhalin 6.21±1.46, n=7 8.25±0.54, n=50 n.s.
Total 7.93±0.30, n=151 8.12±0.22, n=280 n.s.
(3) Branch density
Vologda 8.74±0.37, n=50 9.66±0.22, n=134 <0.001
Moscow 9.60±0.19, n=156 10.28±0.34, n=87 <0.001
Kaluga 10.19±0.26, n=65 9.80±0.32, n=60 n.s.
Sakhalin 10.97±0.56, n=30 14.55±0.49, n=20 <0.001
Total 9.72±0.15, n=301 10.19±0.21, n=301 <0.001
Table 3. Comparison of (1)
branch length between male and
female plants with expressed sex;
(2) branch length between sterile
plants from unisexual popula-
tions; (3) branch density between
male and female plants with ex-
pressed sex. Mean ± ci are shown,
and p is calculated by Mann-
Whytney test.
92 VIKTORIA V. T ELEGANOVA & MICHAEL S. IGNATOV
Region female male
ARC-WSIB 8.9 7.9
ARC-YAK 8.2 7.3
S-UR 10.0 8.7
S-SIB 10.6 8.1
W-SIB 10.7 7.9
S-FE 11.0 8.6
NE 11.6 9.7
C 11.9 9.1
NW 12.1 9.7
E-SIB 13.3 9.5
Total 11.07±0.34 (n=244) 9.01±0.29 (n=189)
dercollected, e.g. by geobotanists for relevés, because
is easy to identify in the field.
Branch length differences
In large-samples study, branches of female plants
were found significantly longer than those of male
plants, p<0.001 for total data (Tables 1&3, Fig. 3).
In herbarium collections branch length of fe-
male plants was found also longer, and this dif-
ference for combined data from all the regions of
Russia was also significant, p<0.001.
Branch length geographic variation
The branch length is apparently correlated with
the climatic condition, which is more clearly seen
in female plants (Fig. 4). Plants with the shorter
branches occur in northern and otherwise climat-
ically severe areas, while the large proportion
(>20%) of plants with long branches was found
in the boreal zone throughout Russia: in lowland
European Russia, Siberia (except Arctic and Yaku-
tia), and south of the Russian Far East. This pat-
tern once more demonstrates that permafrost zone,
covering Yakutia, in many respects, is closer to
Arctic than to the rest of the boreal zone. South-
ern mountains, e.g. Caucasus and South Urals,
seem to be already affected by the summer drought
that makes their living conditions not optimal for
mesic and boreal Ptilium.
Branch density differences
The branch density data (Tables 1&3) show
more variation comparatively with branch length,
and they were found singificant not in all the
large-sample stidies, but in most samples, as well
as in total data female plants have slightly more
dense branch arrangement, p<0.001. Branch den-
sity was studied only in plants with expressed
gender.
Table. 4. Mean branch length of plants from her-
baria. Only regions with no less than 4 samlpes of each
gender are listed (n=305), while total data are calcu-
lated by all the measurements (n=433).
Fig. 4. Proportions of female plants with short, <8 mm branches (black), 8.5-12 mm (grey) and >12 mm (white)
in regions of Russia based on herbarium material (regions with only 1-4 female collections not included).
93
On the reproductive biology of Ptilium crista-castrensis
Difference between sterile and fertile plants
Besides the difference in branch length, male
and female plants are also contrasting in their
differences between fertile and sterile plants: in
male plants this difference is relatively small,
whereas female plants differ from sterile plants
of the same populations considerably (Table 3).
Note, that this pattern has been revealed with the
significance of p<0.001 in all the sampled pop-
ulations (Fig. 3). Male and female plants differ
significantly in branch length, whereas no dif-
ference was found between sterile plants from
male and female unisexual populations (Table 3).
In average, the difference between fertile and
sterile plants in male large-samples was 1.40 mm,
while in female large-samples 3.34. This differ-
ence has significance of p<0.005. In the mea-
surement of herbarium material, the mean dif-
ference between male and sterile plants was 2.75,
while in females 5.57 mm.
Sex expression in different genders
In addition, the percent of fertile plants in male
and female populations was also different (Table
1). In the large-sample study, the mean percent of
fertile plants in male populations was 62.1%, while
in female populations 24.6%. This difference has
however singificance of only p<0.02.
The same difference occurred in the two plots
with mapped genders. The part of the male popu-
lation mapped on a 20 x 20 cm square (Fig. 5)
had 626 plants, 472 (75.4%) with perigonia, while
female one (Fig. 6) had fewer plants, 466, with
only 73 (15.7%) with perichaetia.
In smaller squares, 5 x 5 cm, the number of plants
with perigonia varied from 8 to 50, with 30 as aver-
age, while sterile plants from male population were
from 6 to 14, and 11 as average. The female popu-
lation has corresponding values for squares 5 x 5
cm as follow: plants with perichaetia varied from 0
to 14, and 5 as average, while sterile from 3 to 51,
and 25 as average .
Thus, the selected male population differed
from the female one (1) in higher density of plants,
1.5 cm–1 vs. 1.2 cm–1; (2) in several times higher
percent of plants with gametangia. Certainly, these
are only two subjectively selected plots that might
affect the data considerably. However, the study
of the bisexual plot (Fig. 8) shows that these dif-
ferences remain valid (Tables 5 & 6).
The subdivision of the 85 x 25 cm plot into 85
subsquares allowed to evaluate correlations of
some parameter (Table 6).
Omitting from consideration some obvious
correlations of dependent characters (e.g. between
number of male and total number of plants), the
high correlation was found:
— between the number of female and sterile plants
(cf. also Fig. 7).
— between the number of female plants and plants
with sporophytes.
— percent of male plants in subsquare correlates
(p<0.01) with the total number of plants in
that subsquare, but the stronger correlation
(p><0.001) was found between percent of
male plants and the number of plants with
expressed sex.
Sporophyte distribution
Sporophytes were found in 36 of 85 squares
of bisexual plots, and 35 of them have also male
plants, while in one square without male plants
the nearest plant with perigonia was at the dis-
tance of 3.5 cm from a plant with sporophyte. In
all other cases the distance from plants with sporo-
phytes never exceeded 1.5 cm.
DISCUSSION
1. Herbarium collections demonstrate the female
bias in Ptilium, whereas the studied mixed popula-
tion (one presented here and some preliminary ob-
servation in Zvenigorod biological station) demon-
strate that mixed populations have a male sex bias.
This incongruence can be explained by the differ-
ence of the study method. Similar differences be-
tween herbarium and population study were outlined
by Bisang & Hedenäs (2005). Cronberg et al. (2003)
demonstrated also the difference in the male:female
ratio between genets and ramets of Plagiomnium
affine. At least partly, this incongruence in Ptilium
may be explained by collector preferences to gather
larger plants and plants with sporophytes, avoiding
Male Female Sterile
male, n=16 30.36±6.92 — 9.63±1.31
female, n=16 — 4.56±2.27 24.56±7.10
mix, n=85 16.80±2.50 2.09±0.41 10.80±1.67
Table 5. The mean number (±ci) of plants of Ptilium,
of each sex and sterile ones, in 5 x 5 subsquares in
plots with mapped genders (male, Fig. 5; female, Fig.
6; mixed, Fig. 8) .
94 VIKTORIA V. T ELEGANOVA & MICHAEL S. IGNATOV
Fig. 5. Map of plot of 20 x
20 cm of almost pure male
population of Ptilium crista-
castrensis from Zvenigorod
biological station (50% of
natural size): Squares – male
plants, open circles – sterile
plants (triangule – one female
plant, asterisk – one plant
with young sporophyte).
Fig. 6. Map of plot of 20 x
20 cm of female population of
Ptilium crista-castrensis from
Zvenigorod biological sta-
tion: Triangules – female
plants, open circles – sterile
plants.
95
On the reproductive biology of Ptilium crista-castrensis
male plants that might be considered simply unde-
veloped, thus not worthy to collect.
2. The resistance of female sex to more severe
conditions was not much discussed, but there are
many examples for that. Certain species, e.g. Hyp-
num curpessiforme and Leucodon sciuroides, are
known with sporophytes in Russia, mostly in Cau-
casus and western regions of European Russia with
a relatively mild climate, whereas throughout most
of Siberia only female plants occur (Ignatov, un-
published). Bisang and Hedenäs (2005) also re-
ported declining of male sex in Hypnum cupres-
siforme in high mountains of Africa. This might
relate to very short vegetative period that is not
enough for development of male gametangia,
which require longer time than the development
of female ones (e.g. Longton & Schuster, 1983;
Milne, 2001; Stark et al., 2005).
3. The larger size of female plants and the big-
ger difference of fertile and sterile plants (of pre-
sumably the same sex) imply that the reproduc-
tive effort of female plants is higher than in male
plants. There are several ways to explain the dif-
ference between sterile and gametangia-bearing
plants in male and female sexes. (A) Only better
developed and stronger female plants are able to
develop gametangia, while virtually any male plant
is able to do this; (B) Female plants after consider-
able effort for gametangia production [that proba-
bly correlates with development of longer branch-
es] need a certain time for the recovery, and during
this recovery year(s), plants do not waste energy
for producing longer branches. These alternative
hypotheses probably can be tested in the future.
4. The rare occurrence of sporophytes is ex-
plained by the rare occurrence of bisexual popu-
lations and spatial segregation of sexes. Even in
bisexual populations the grouping of male and fe-
male plants is evident (Fig. 8). A similar pattern
has been demonstrated for many dioicous species,
although the reason for that is not fully understood
yet. Cameron & Wyatt (1990) found that in
Splachnum most populations are female-biased,
whereas under experimental conditions, and es-
pecially when growing in full sun and on more
acid substrate, the male sex becomes more repre-
sented and in many cases populations are male-
biased. It can be speculated that the micro-mosaic
in the forest floor may explain certain differentia-
tion in sexual heterogenity in Ptilium populations,
although this would be difficult to demonstrate for
pleurocarps that are readily spreading vegetative-
ly. Another possible explanation is that the two sex-
es may compete, resulting in spatial segregation;
this mechanism was recently demonstrated in
Marchantia (Garsia-Ramos & al., 2007).
5. An intriguing parallel can be drawn with the
Tetraphis pellucida reproductive biology (Kimmer-
f sterile m+f m+f+st S+ %m
male –0.197 ns –0.324** 0.976*** 0.698*** 0.065ns 0.637***
female — 0.522*** 0.022ns 0.348** 0.714*** –0.568***
sterile — –0.213* 0.431*** 0.260* –315**
m+f — 0.790*** 0.225* 0.522***
m+f+s — 0.371*** 0.284**
S+ — –0.260*
Table 6. Correlation found in the 85 subsquares (5 x 5 cm) of the mapped plot of Ptilium in Fig. 7. Correlation
(r) was calculated in PAST by means of linear model between: (1) number of male plants; (2) number of female
plants;(3) number of sterile plants; (4) all plants with expressed gender; (5) total number of plants; (6) plants with
sporophytes; (7) percent of male plants; p>0.05 – ns; p<0.05 – *; p<0.01 – **; p<0.001 – ***.
5
234561
10
15
20
25
30
35
40
Fig. 7. Correlation between number of sterile plants (Y)
and female plants (X) of Ptilium crista-castrensis in 85
subsquares of 5x5 cm of mapped plot in Fig. 8 (cf. Table
6).
96 VIKTORIA V. T ELEGANOVA & MICHAEL S. IGNATOV
er, 1991). In that species the density of plants in a
population (that was studied with removal of 10 to
75% of plants from tufts) affect the proportion of
sexes, so the looser tufts develop a higher propor-
tion of female plants. Drawing a parallel to Ptili-
um, this allows one to hypothesize that some fe-
male plants may exist among dense male groups,
but not develop gametangia there. The experiments
with thinning of male populations of Ptilium may
demonstrate if this takes place or not.
6. About an equal distance from males and fer-
tilized and non-fertilized females was reported for
bisexual populations of dioicous Hyophila invo-
luta (Hook.) A.Jaeger and Barbula agraria Hedw.
(Mota de Oliveira, 2005). In Ptilium we found the
same, however, likely by another, although un-
clear reason. Ptilium differs from these two Potti-
aceous mosses that are strongly female biased, in
more numerous male plants; the rarity of the lat-
ter may be invoked to explain the sporophyte rar-
ity in Hyophila and Barbula. Glime (2007) report-
BISANG, I., L. HEDENÄS 2005. Sex ratio patterns in dio-
icous bryophytes re-visited. – J. Bryol. 27: 207-219.
CAMERON, R.G. & R. WYATT 1990. Spatial patterns and
sex ratios in dioecious and monoecious mosses of the ge-
nus Splachnum. – Bryologist 93: 161-166.
CRONBERG, N., K. ANDERSON, R. WYATT & I.J.
ODRZYKOSKI 2003. Clonal distribution, fertility and sex
ratios in the moss Plagiomnium affine (Bland.)T.Kop. in
forests of contrasting age. – J. Bryol. 25: 155-162.
GARSIA-RAMOS, G., CH. STIEHA, D.N. MCLETCHIE &
P.H. CROWLEY 2007. Persistence of the sexes in metapo-
pulations under intense asymmetric competition. – J. Ecol.
95: 937-950.
GLIME, J.M. 2007. Bryophyte Ecology. Vol. 1. Physiologi-
cal Ecology. – Ebook sponsored by Michigan Technolo-
gical University and the International Association of Bry-
ologists. Accessed on 25 December 2007 at <http://www.
bryoecol.mtu.edu/>
GOFFINET, B. & W.R. BUCK 2004. Systematics of the Bryo-
phyta (mosses): from molecules to a revised classification.
– Monographs in Systematic Botany from the Missouri
Botanical Garden 98: 205-239.
HAMMER, O., D.A.T.HARPER & P.D.RYAN 2008. PAST-
PAlaeontologicalSTatistics,ver.1.81. – http://folk.uio.no/
ohammer/past
IGNATOV, M.S., O.M.AFONINA, E.A. IGNATOVA et al.
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[IGNATOV, M.S. & E.A. IGNATOVA] ИГНАТОВ М.С., Е.А.
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ed the maximal distance of fertilizing in pleuro-
carps to be 6 to 10 cm. In Ptilium where the peri-
gonia are always faced downwards, this distance
can be somewhat shorter, and this agree with the
obtained data of maximal 3.5 cm.
7. Among the further questions should be also
the influence of the climatic condition of the giv-
en year. In 2006, after a very dry winter (autumn
of 2005 was very dry and turned to cold winter
very abruptly, thus omitting wet period with tem-
peratures 0 to +10°C), the sporophytes in Zvenig-
orod forest were very rare. In 2007, however, af-
ter ‘normal’ winter, i.e. with expanded wet and
snowless periods in autumn and spring, Ptilium
sporophytes were obviously more numerous.
ACKNOWLEDGEMENTS
We are grateful to Sanna Laaka-Lindberg for
valuable criticism, and also to Janice Glime for
suggestions on the manuscript and improving
English. The work was partly supported by the
RFBR grant 07-04-00013.
97
On the reproductive biology of Ptilium crista-castrensis
Fig. 8 (see also next page). Map of mat of Ptilium crista-castrensis (85 x 25 cm): Blue – male plants; red –
female plants; white – sterile plants, red with white dot – plants with sporophytes.
98 VIKTORIA V. T ELEGANOVA & MICHAEL S. IGNATOV
Fig. 8 (see also previous page). Map of mat of Ptilium crista-castrensis (85 x 25 cm): Blue – male plants; red
– female plants; white – sterile plants, red with white dot – plants with sporophytes.
