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Organization for Flora Neotropica
Dicranaceae: Campylopodioideae, Paraleucobryoideae Author(s):
Jan-Peter Frahm Source: Flora Neotropica, Vol. 54, Dicranaceae:
Campylopodioideae, Paraleucobryoideae (Feb. 21,
1991), pp. 1-237Published by: on behalf of New York Botanical
Garden Press Organization for Flora NeotropicaStable URL:
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FLORA NEOTROPICA
MONOGRAPH 54
DICRANACEAE: CAMPYLOPODIOIDEAE, PARALEUCOBRYOIDEAE
by
Jan-Peter Frahm Department of Botany University of Duisburg
Germany
c^s [
\TYROPIOC
Of CANCER
FLORAO NEOTROPICA.
Published for
Organization for Flora Neotropica
by The New York Botanical Garden
New York
Issued 21 February 1991
^^ K^iN., *9
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Copyright ? 1991
The New York Botanical Garden
Published by The New York Botanical Garden
Bronx, New York 10458
International Standard Serial Number 0071-5794
Library of Congress Cataloging in Publication Data Flora
neotropica. - Monograph no. 1 - New York: Published
for Organization for Flora Neotropica by the New York Botanical
Garden, 1968-
v.: ill.; 26 cm.
Irregular. Each issue has distinctive title. Separately
cataloged and classified in LC before monograph no. 40. ISSN
0071-5794 = Flora neotropica.
1. Botany-Latin America-Classification-Collected works. 2.
Botany- Tropics-Classification-Collected works. 3.
Botany-Classification-Col- lected works. I. Organization for Flora
Neotropica. II. New York Botanical Garden.
QK205.F58 581.98'012-dcl9 85-647083 AACR 2 MARC-S
Library of Congress [8508] ISBN 0-89327-363-5
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DICRANACEAE: CAMPYLOPODIOIDEAE, PARALEUCOBRYOIDEAE
JAN-PETER FRAHM'
TABLE OF CONTENTS Introduction
.................................................................................
2 H istorical A ccount .............
............................................................... 4 A
natom y .... . . . .
....................................................................
5
G am eto phyte
............................................................................
5 L eav es .....
......................................................................
5 C o sta . ..... .. ..... ... ......................
................. ...... ................. . 6 R h izo id s
...........................................................................
9 Stem s ..........................................................
.................. 10 Calyptrae
...........................................................................
10
Sporophyte .................................
......................................... . 10 S etae ..........
....... ........ ................................. .. .......
......... ... . 10 C apsules
.............................................................................
12 Stomata
...........................................................................
12 A nnulus
.............................................................................
12 Peristom
e...........................................................................
12
Spores...............................................................................
14
C ytology ................................
.......................................... 14 C h em istry
...................................................................................
16 Geography ....................................................
........................ 17 O rigin and Evolution
.........................................................................
20 E co lo gy .. ................... ....... ...................
........................... 2 2
S u b strate ........................................
..................................... 22 Structural Adaptations
..........
.......................................................... 22
W ater Storage
........................................................................
22 Resistance to W ater Loss
..............................................................
23
Uptake of W ater and Nutrients
................................................ ........... 23
Sexual R eproduction
......................................................................
23 Vegetative Reproduction
.................................................................
24
System atic Treatm ent
.........................................................................
24 Cam pylopodioideae.
......................................................................
24
1. A tractylocarpus
....................................................................
25 2. Bryohum bertia
....................................................................
31 3. Cam pylopodium
...................................................................
36 4. Campylopus .............................
......................................... 37 5. D icranodontium
...................................................................
196 6. M icrocam pylopus
..................................................................
200 7. Pilopogon
.........................................................................203
8. Sphaerothecium
...................................................................
216
Paraleucobryoideae
.......................................................................
217 1. C am pylopodiella .............
................................................. 220 2. B rothera
..........................................................................
224 3. Paraleucobryum
...................................................................
225
A cknow ledgm ents .......................................
................................... 229 Literature Cited
..............................................................................
229 Index to Scientific Names .............
..................................... ............... 232
' Department of Botany, University of Duisburg, Fachbereich 6,
Postfach 101629, 4100 Duisburg, Federal Republic of Germany.
1
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~~~~~~~~~~~~2 ~~~Flora Neotropica
ABSTRACT
Frahm, J.-P. (Dept. of Botany, University of Duisburg, 4100
Duisburg, Federal Republic of Germany). Dicranaceae:
Campylopodioideae, Paraleucobryoideae. Flora Neotropica 54: 1-238.
1991. The Campylopodioideae and Paraleucobryoideae are closely
related subfam- ilies of the Dicranaceae (Musci). Within the
Dicranaceae, both are characterized by a broad costa with a high
variation in anatomical structures. The Campylopodioideae in the
Neo- tropics consist of eight genera: Atractylocarpus Williams with
three species, Bryohumbertia Portier de la Varde & Theriot with
one, Campylopodium (C. Miiller) Bescherelle with one, Campylopus
Bridel with 65, Dicranodontium Bruch, Schimper & Giimbel with
four, Mi- crocampylopus (C. Miiller) Fleischer with one, Pilopogon
Bridel with six, and Sphaerothecium with one species. The
Paraleucobryoideae in the Neotropics consist of three genera:
Brothera C. Miiller with one species, Campylopodiella Cardot with
two, and Paraleucobryum (Lim- pricht) Loeske with two species. All
87 species, as well as infraspecific taxa are described and
illustrated.
RESUMEN
Campylopodioideae y Paraleucobryoideae son subfamilias
estrechamente afines a las Di- cranaceae (Musci). Dentro de las
Dicranaceae ambas subfamilias se caracterizan por una costa ancha
con una gran variaci6n de estructuras anat6micas. Las
Campylopodioideae en los Neotr6picos consisten de 8 g6neros:
Atractylocarpus Williams con 3 especies, Bryohum- bertia Portier de
la Varde & Theriot con 1 especie, Campylopodium (C. Miiller)
Bescherelle con 1 especie, Campylopus Bridel con 65 especies,
Dicranodontium Bruch, Schimper & Giimbel con 4 especies,
Microcampylopus (C. Miller) Fleischer con 1 especie, Pilopogon
Bridel con 6 especies y Sphaerothecium con 1 especie. La
Paraleucobryoideae en los Neo- tr6picos consiste de 3 g6neros:
Brothera C. Miiller con I especie, Campylopodiella Cardot con 2
especies y Paraleucobryum (Limpricht) Loeske con 2 especies. Todas
las 87 especies asi como los taxones infraespecificos estan
descritos e ilustrados.
INTRODUCTION The Campylopodioideae and Paraleucobryoi-
deae are subfamilies of the Dicranaceae. This family of mosses
is characterized by narrowly lanceolate leaves which are sometimes
secund or falcate with (usually smooth) elongate to quad- rate
laminal cells which are often differentiated into basal and upper
laminal cells, a single per- current or excurrent costa, and the
frequent oc- currence of differentiated alar cells. The sporo-
phytes are usually terminal with mostly cucullate calyptrae and
cylindrical to ovoid, erect or curved capsules. The plants are
erect and can be robust, forming dense mats, or minute. The
Dicranaceae belong to an evolutionary line of the superorder
Haplolepideae with a peristome consisting of 16 teeth. The
peristome teeth of the Dicranaceae are entire or divided into 2
(rarely 3) prongs and usually are vertically striate on the outer
surface,
an ornamentation which is frequently found in the Dicranales and
therefore called the "dicra- noid" type.
Unfortunately, there are transitions between the two
subfamilies. Certain species of Campy- lopus cannot be
distinguished vegetatively from species of Paraleucobryum, since
they all have a "leucobryoid" structure of the leaves with ven-
tral and dorsal rows of hyalocysts. Whether this is due to
phylogenetic descent or the consequence of an independent evolution
of this leaf anatomy is not known.
The Campylopodioideae were established by Brotherus (1924).
Brotherus included 10 genera in this subfamily: Metzlerella,
Microdus, Dicra- nella, Microcampylopus, Campylopodium,
Campylopodiella, Pilopogon, Campylopus, Thysanomitrion and
Dicranodontium. Of these genera, Thysanomitrion is now included in
Cam- pylopus as a subgenus, Microdus and Dicranella
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Introduction 3
are placed in a separate subfamily, Dicranel- loideae, and
Campylopodiella is placed in the Paraleucobryoideae (Miiller &
Frahm, 1987). In addition the genera Bryohumbertia and Sphaero-
thecium are treated here (with species formerly included in
Campylopus). The circumscription of the Campylopodioideae used here
is similar to that of Walther (1983). Walther, however, seg-
regated Campylopodium and Microcampylopus into different
subfamilies (Dicranelloideae and Campylopodioideae), although both
genera are very closely related and can be regarded as sub- genera
of one genus (Giese & Frahm, 1985a), and included Mitrobryum
and Maireola in the Campylopodioideae. The placement of Mitro-
bryum is not clear since this genus differs from all other
Dicranaceae by its mitrate calyptrae. Maireola has been synonymized
with Ditrichum (Frahm & Seppelt, 1987). The genus Bryotestua is
not taken into account here because it is based on sterile plants.
Another genus, Bartleya, has been placed into the synonymy
ofDicranella cer- viculata (Crum & Anderson, 1981).
The systematics of the Campylopodioideae have been discussed by
Frahm (1986) but there is still no satisfactory analysis of this
subfamily. The circumscription given by Brotherus (1924) was
ill-defined and based on five characters, three of which (dioicous
sexuality, differentiated alar cells, and lack of stomata) were
restricted by the word "mostly," a fourth character (differentiated
perichaetial leaves) separated genera such as Di- cranella and
Anisothecium into different subfam- ilies, genera which are today
usually accepted as one genus. A fifth character (leaves gradually
thinner towards the margins) is not applicable to most genera. This
confusing assemblage of gen- era lacked revisions and monographs to
provide the basic information for generic concepts. A conspicuous
character met in most of these gen- era is the sinuose seta.
Therefore it is commonly regarded as characteristic of the
subfamily. Only Pilopogon and Atractylocarpus have straight se-
tae, but these genera are virtually gametophyti- cally identical to
Campylopus and Dicranodon- tium. Sinuose setae, however, also occur
in Cynodontium (Dicranaceae), Grimmia (Grim- miaceae) and
Campylostelium (Ptychomitri- aceae) and have apparently evolved
indepen- dently several times. This may be the case for
Campylopodium and Microcampylopus, which usually are placed in the
Campylopodioideae be-
cause of their sinuose setae and thus their "cam- pylopodioid"
appearance, but fit better in the Dicranelloideae in all other
respects. Therefore, as treated here, the circumscription of the
Cam- pylopodioideae is probably artificial.
Whereas most genera of Campylopodioideae comprise between 2 and
12 species worldwide, the genus Campylopus has about 180 species
and is thus one of the largest genera of mosses.
With the exception of Campylopus and Di- cranodontium, all
genera of Campylopodioideae have been revised: Campylopodium (Giese
& Frahm, 1985a), Microcampylopus (Giese & Frahm, 1985b),
Atractylocarpus (Padberg & Frahm, 1985), Pilopogon (Frahm,
1983a), Bryo- humbertia (Frahm, 1982a), and Sphaerothecium (Frahm,
1986b). Only two subgenera of Cam- pylopus have been treated
worldwide (Thysano- mitrion, Frahm, 1984a, and Campylopidulum,
Frahm, 1986c). For the rest of the genus only local treatments
exist for South America (Frahm, 1975a, 1975b, 1977, 1978a, 1979a,
1979b, 1979c, 1980a, 1981a, 1981b, 1982c, 1984c, 1986d; Frahm &
Hegewald, 1979; Frahm & Sipman, 1978), Africa (Frahm, 1985a),
and Australasia (Bartlett & Frahm, 1983; Catcheside &
Frahm, 1983; Frahm, 1984b, 1987a; Frahm & Mo- hamed, 1987;
Frahm et al., 1985) as well as tax- onomic treatments of single
taxa (Frahm, 1974) mainly published in 14 continuations of the se-
ries "Taxonomische Notizen zur Gattung Cam- pylopus" (Frahm, 1975c,
1976a, 1976b, 1976c, 1978b, 1978c, 1979d, 1980b, 1981c, 1981d,
1982d, 1985b, 1985c).
In these publications all character states need- ed for
classification have been critically evalu- ated, the range of
expression of these character states overviewed, the delimitation
of genera de- fined and corrected, and many species placed into
synonymy. Worldwide, the number of spe- cies in Campylopus has been
reduced from about 720 to 180, in Microcampylopus from 12 to 2, in
Pilopogon from 14 to 8.
The Paraleucobryoideae were also established by Brotherus
(1924). Brotherus included the gen- era Paraleucobryum and Brothera
and based the subfamily on the broad costa with a median row of
chlorocysts, differentiated alar cells, a straight seta and
symmetrical, smooth capsules. Recently Walther (1983) transferred
Campylopodiella to this subfamily, based on the close relationship
of this genus to Brothera. The entire subfamily
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4 Flora Neotropica
has been monographed by Miller and Frahm (1987).
HISTORICAL ACCOUNT Campylopus was described by Bridel in
1819.
The name was chosen to characterize the curved setae (derived
from Greek campylos = curved and pous = foot). Bridel included
several species with curved setae in this genus which have noth-
ing in common except this kind of seta, for example, species later
placed in Grimmia or Ra- comitrium. Species placed presently in
Campy- lopus were mostly described as species of Di- cranum, and
many authors (e.g., Carl Miiller) continued to use the name
Dicranum to describe hundreds of species applicable to Campylopus.
The exploration of the tropics increased the number of species in
this genus dramatically. The Index Muscorum (Wijk et al., 1959)
lists more than 1000 species, about 720 of which were le-
gitimate.
The high number of species described (e.g., 320 legitimate
species cited in the Index Mus- corum for Latin America, and a
total of 260 spe- cies described from Africa) prohibited an over-
view of this genus. Different taxonomic concepts used in the last
century led to the description of growth forms as separate species,
and the lack of phytogeographic knowledge and pre-Darwinian
theories on the origin of species resulted in the independent
description of species from every country and island. The lack of
knowledge of the variability of species and especially the use of
variable character states, such as the transverse section of the
costa, made this genus a difficult one. It enormously raised the
number of species described; species which were neither illustrated
nor sufficiently described.
During the last century many new genera were established or
raised from subgeneric status.
Dicranodontium was introduced in 1847 for species formerly
placed in Dicranum or Cam- pylopus.
Campylopodium, originally described as a sec- tion of
Aongstroemia was raised to the rank of a genus in 1873 on the basis
of its curved setae. At one time 27 different species were
included; these have been reduced to two (Giese & Frahm,
1985a).
Microcampylopus was originally established as a subgenus of
Campylopus in 1899. It was raised
to the rank of a genus in 1900, and again reduced to the rank of
a subgenus in 1933. Of the 27 species included originally, three
were retained by Giese and Frahm (1985b).
Pilopogon was introduced in 1826. In 1901 Brotherus placed all
species of the genus Thysa- nomitrion in a subgenus of Pilopogon
because of similarities of the peristome. This caused con- fusion,
because Thysanomitrion was usually re- garded as a subgenus of
Campylopus. A mono- graph of the genus (Frahm 1983a) maintained
eight species worldwide, seven of them neotrop- ic.
The species of Bryohumbertia were originally included in
Campylopus. The genus was based on an African species, described in
1939, which was regarded as more or less closely related or even
synonymous with Campylopus. A re-eval- uation of its character
states and additional ul- trastructural differences led to the
establishment of this genus with three species, one each in the
neotropics, tropical Africa and SE Asia (Frahm, 1982a).
Sphaerothecium was introduced in 1865 for a species from
Colombia. In 1873 another species was added from Sri Lanka. For
more than a hun- dred years these two species were the only rep-
resentatives of this genus until a third species, from Africa and
formerly a member of Cam- pylopus, proved to be a member of this
genus (Frahm, 1986b).
Atractylocarpus was described by Mitten in 1869. Nineteen
legitimate species were listed in the Index Muscorum. Of these nine
were ac- cepted in a recent revision of the genus (Padberg &
Frahm, 1985).
The subfamily Paraleucobryoideae was de- fined by Brotherus
(1924) to include the genera Paraleucobryum and Brothera. Walther
(1983) added Campylopodiella, formerly included in the
Campylopodioideae, because of its structural af- finities to
Brothera.
Campylopodiella was described from Sikkim. Later an African and
a Himalayan species were added. A revision showed the African
species to be a species of Campylopus, the Himalayan spe- cies to
be identical with the type species, and an andine species formerly
regarded as Campylopus to be a member of Campylopodiella (Frahm,
1984c). In further studies (Miiller & Frahm, 1987) a third
species, again from the Andes, was in- cluded in Campylopodiella.
Recently a fourth
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Anatomy 5
species was added from Papua New Guinea (Frahm et al.,
1988).
Brothera was originally based on two nomina nuda from Asia.
Brotherus (1901) reduced these names to synonyms of B. leana from
North America, formerly included in Campylopus, and added a second
species. This second species is a species of Campylopodiella
(Frahm, 1984c), and so the genus is still monotypic.
Paraleucobryum was first introduced by Lind- berg (1886) as a
subgenus of Dicranum. Loeske (1907) raised it to the rank of genus,
and included three holarctic species. Subsequently other spe- cies
were transferred to this genus from Dicra- num or described as new.
All these new com- binations and new species have been reduced by
Miiller and Frahm (1987).
ANATOMY GAMETOPHYTE
Most genera of Campylopodioideae and Para- leucobryoideae are
dioicous. Only Atractylocar- pus is autoicous and Campylopodiella
is paroi- cous. Conspicuously, these latter genera have species
with small ranges. Dioicism is probably responsible for the broad
morphological range of character states, especially in the genus
Cam- pylopus, that are the results of numerous genetic variations
resulting from out-breeding. Dioicy also has disadvantages, for
example in long dis- tance dispersal, when only one sex is present
in one habitat and effective methods of vegetative propagation are
required to fill the gap between heterosexual populations and to
allow fertiliza- tion.
The sex of sterile plants cannot be determined. Fertile plants
especially of the genera Campy- lopus and Pilopogon show, in part,
a morpho- logical differentiation due to heterodioicism. In C.
fragilis dwarf males have been observed nest- ing in female tufts.
Fertile plants of a number of species produce bud-like stem apices
consisting of broader and blunter leaves. As in many other mosses
this concerns mostly male plants, which produce flower-like
gametangia that function for dispersal of the spermatozoids by a
splash cup mechanism. More rarely, female plants also pro- duce
terminal buds which contain several peri- chaetia. There are also
species that lack differ- entiation, or which display either hardly
any or,
conversely, display extreme differentiation of gametangia.
Conspicuously, the differentiation of bud-like perichaetia is
confined to species with high fertility and it thus can be assumed
that antherozoid dispersal is effective. Special differ- entiations
are found in a group of species with piliferous leaves such as
Campylopus introflexus, C. pilifer, C. julaceus and C. aemulans.
Other species are mostly found fertile and thus give a comose
appearance as in C. occultus, C. pauper or C. zygodonticarpus. The
highest development of such perichaetia is found in Campylopus
subg. Thysanomitrion. Here the perichaetia are devel- oped on
appressed foliate stalks, especially the species occurring in SE
Asia. This character is not developed in the only subantarctic
represen- tative of this subgenus (C. clavatus) which is re- garded
as most primitive, and is hardly devel- oped in the only neotropic
representative (C. richardii).
Leaves
The leaves are lanceolate to narrowly lanceo- late in shape,
gradually narrowing to a subulate apex. The margins are usually
entire or serrate or denticulate only in the apex. Due to the
broad, often excurrent costa, the lamina is narrow and rarely
reaches to the leaf tip, but often vanishes near midleaf. The
lamina is always unistratose. Laminal cells can be differentiated
into alar cells, basal and upper laminal cells. Alar cells may be
differentiated or not. They are not developed in Microcampylopus
and Campylopodium but dif- ferentiated in all other genera, either
weakly or strongly. Although alar cells can be very con- spicuous
in some species and hardly developed in others, this is apparently
not a specific char- acter. In many species this character varies
much, obviously controlled by the habitat. Alar cells function in
water uptake from capillary water along the stem or the tomentum to
the leaf. Therefore, alar cells are usually lacking in plants of
wet habitats. In Campylopus pilifer specimens from rainforests show
no alar cells since they receive atmospheric water taken up by the
leaf surfaces. Specimens from dry habitats have dif- ferentiated
alar cells. Alar cells are especially well differentiated in plants
growing on wet rocks ex- posed to the sun, which have a high
evaporation rate. In contrast to the older literature, which used
this character for differentiation of species,
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6 Flora Neotropica
the presence of alar cells is regarded today as controlled by
modifications and thus usually ne- glected as a useful character
for separation of species.
Basal laminal cells differ by their larger size and different
shape from upper laminal cells. They can be either hyaline and thin
walled or incras- sate. Species with hyaline basal laminal cells
usu- ally show a distinct differentiation from the in- crassate
upper laminal cells. The basal cells extend higher up along the
margins and are thus V-shaped in mass. Hyaline basal laminal cells
sheathing the stem function for water uptake and are found
especially in species of wet or mesic habitats. Incrassate laminal
cells can be smooth or pitted. Basal laminal cells are
differentiated into smaller outer and larger inner ones. The outer
can be narrow and hyaline and forming a border 2-12 cells wide, or
smaller and shorter. The upper laminal cells can be quadrate,
oblique, oval or shortly rectangular. They are long-rectan- gular
only in Dicranodontium.
Perichaetial leaves are widened at base and suddenly contracted
to an elongate point. The broad sheathing base suggests a narrower
costa, which is, however, not narrower but as broad as in normal
leaves. The perichaetia themselves are surrounded by another type
of broad involucral leaves which are blunt in male plants but show
longly excurrent costas in female plants.
Special perichaetial leaves are found in Pilo- pogon, sheathing
nearly the whole seta. This can be interpreted as another strategy
to protect the young sporophyte. In genera of Campylopodioi- deae
with sinuose setae the capsules develop pro- tected between the
comal leaves. This is not pos- sible with straight setae but in
this case the perichaetial leaves take over this function. This may
also cause the longer shape of the capsules in genera with straight
setae in contrast to the stout capsules of genera with sinuose
capsules which stick between the perichaetial leaves.
Costa
The costa is percurrent or excurrent in all gen- era treated
here. In Campylopus the excurrent costae may be concolorous or
hyaline, forming whitish hairtips. These hairpoints can be erect
(e.g., C. pilifer), reflexed (C. introflexus) or re- curved (C.
griseus) and function in the reduction of evaporation. The length
of the hairpoint is
determined by modification, since in all these species epilose
plants can be found in shady habi- tats.
The costa is the most prominent character of both subfamilies.
In contrast to most other moss- es, the costa fills between 1/3 and
% of the leaf width. In this way the usually unistratose lamina
with a narrow costa of most mosses is replaced here, more or less
totally, by a highly differen- tiated anatomical structure
providing water stor- age, photosynthesis and mechanical protection
against shrinking.
The costa is composed in most genera of Di- cranaceae, except
numerous species of Campy- lopus and all species of
Paraleucobryoideae, by a common dicranoid type. It consists of
(Fig. 1):
1. A ventral chlorophyllose epidermis. 2. A multilayered band of
long, narrow cells,
which are called stereids. Since they resemble similar cells in
the central strand of the stem which function for water conduction,
they are sometimes also called hydroids.
3. A median layer of enlarged cells, usually named deuters. The
term deuter, of German or- igin, is merely descriptive and means
pointer cell; it refers to conspicuously large cells in the median
of a transverse section of a costa. This term has been used for a
median band of enlarged cells in the Polytrichaceae. In that family
these cells con- duct water, and therefore they are also called
hydroids. In the Campylopodioideae, however, these cells are
chlorophyllose ("chlorocysts") and are thus functionally different.
Some authors re- place the term deuter by eurycysts (which means,
however, the same and does not regard the func- tion of these
cells), others by "duces" (Latin for guide cells).
4. A dorsal band of stereids. 5. A dorsal epidermis. This
structure primarily provides a firm struc-
ture and possible water supply by the two bands of stereids and
assimilation by the ventral, me- dian and dorsal cell layers.
In Campylopus an enormous variation of this type of costa is
found, which is presumably the reason for the rich speciation in
this genus. It allows the species to adapt to a broad spectrum of
ecological niches (Frahm, 1987b). The vari- ation (Fig. 2)
concerns:
a. the change, by gradual enlargement from ventral stereids to
substereids, small hyalocysts with firm walls and large hyalocysts
with lax walls.
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Anatomy 7
AigSfetea^ B^ssillSy t Al
if ,
FIG. 1. Transverse sections of leaves in different genera of
Campylopodioideae and Paraleucobryoideae. A. Campylopodiella
stenocarpa (Maslin s.n., NY). B. Paraleucobryum longifolium (Crum
1851, DUKE). C. Pilo- pogon macrocarpus (Allioni 8056, H-BR). D.
Atractylocarpus longisetus (Pringle 10603, NY). E. Campylopodium
medium (Steere 6831, MO). F. Microcampylopus curvisetus (Sartorius
60, BM).
b. the change from dorsal groups of stereids to substereids or
single large cells. The stereids are sometimes named stenocysts,
the large cells replacing a group of stereids, socii, comites, Be-
gleiter or leptoids. These terms are taken from the structure of
the costa in the Polytrichaceae in which these cells accompany the
deuter cells
("socii, comites, Begleiter") and function for the transport of
nutrients ("leptoids"), and form- together with the deuter cells-a
primitive con- duction tissue, with phloem (leptom) and xylem
(hadrom) elements. This is, however, not the case in Dicranaceae
and therefore an application of these terms should be avoided. All
possible tran-
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8 Flora Neotropica
A
B W
C O FIG. 2. Transverse sections of different types of costae in
the genus Campylopus. A. Costa with large
ventral hyalocysts in Campylopus pittieri (Cleef 8806, U). B.
Costa with ventral substereids in Campylopus surinamensis (Mohr
1868, NY). C. Costa with ventral stereids in Campylopus uleanus
(Ule 148, H-BR).
sitions are possible from a group of stereids to a single larger
cell by omission of one or more cell divisions (Frahm, 1982e).
c. the change from smooth dorsal leaves to ribbed or lamellose
surfaces by division of the chlorophyllose dorsal epidermal
cells.
As shown by the confusion of different terms used for the
structure of the costa, there is no consistent usage. It is
proposed to use the de- scriptive terms hyalocysts, eurycysts (for
deuter cells), stenocysts and chlorocysts, although in the
systematic part the term stenocysts is replaced by the more common
and better understandable term stereids.
There is variation in the structure of the costa in one leaf and
in plants of different habitats. The length of dorsal lamellae
decreases to the leaf base and the width of ventral hyalocysts
increas- es to the leaf base. Thus leaves may be lamellose
FIG. 3. Transverse section of the costa of Cam-
B 1!.
pylopus pilifer (Griffin et al. 92, FLAS). A. The upper third of
the leaf. B. The lower third of the leaf.
in the upper part and ridged on the basal part (Fig. 3) or
ridged in the upper part and smooth in the basal part. Ventral
stereids in the upper part of the leaf can change to substereids in
the basal part or substereids in the upper part can change to
hyalocysts in the basal part. In humid habitats, dorsal stereids
can get larger and change to substereids, and dorsal lamellae can
get short- er.
In the Paraleucobryoideae the costa consists of a median band of
chlorocysts (perhaps com- parable to the deuter cells of the
Campylopo- dioideae) and ventral and dorsal hyalocysts. The median
chlorocysts are single in Paraleucobryum and Brothera but divided
into 2 to 4 in Cam- pylopodiella. In Paraleucobryum a dorsal band
of chlorocysts can be present. This situation links Paraleucobryum
with certain species of Cam- pylopus (Frahm, 1982b). Considering
the basic sporophytic differences between both genera this can be
interpreted rather as independent devel- opment than as
phylogenetic linkage. On the oth- er hand, Ligrone (1985) has
derived the structure of the leucobryaceous leaf from a dicranoid
an- cestor, which is also hypothetically possible and
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Anatomy 9
phylogenetically even more likely, since Leuco- bryum has the
same sporophyte as species of Dicranum.
The presence of dorsal and ventral bands of stereids in most
other Dicranaceae can be re- garded as the basic structure from
which the ten- dency to develop hyalocysts seems to be derived. The
presence of ventral and dorsal bands of stereids in the highly
advanced subgenus Thysa- nomitrion need not be a contradiction.
These species, all except for one, occur in the tropics, where the
conservative structure of the costa with stereid bands has
advantages as protection against shrinking and for water
support.
The ecological significance of the costa of Campylopus has been
discussed by comparisons of species pairs differing only in a
single character in the costal anatomy and a different habitat
(Frahm, 1987b). The differentiation of the costa concerns several
characters.
1. Lamellose and non-lamellose costae. There are all possible
transitions between costae with smooth dorsal sides and dorsal
sides with la- mellae up to six cells high in different species of
this genus. Generally, species with high lamellae occur in habitats
which can easily dry up. Species with long lamellae can store water
and thus ex- tend the photosynthetically active period in dry
habitats. Examples for this adaptation are C. trachyblepharon (on
dry sand in coastal areas of SE Brazil), C. pilifer on exposed
rocks, and C. lamellinervis in dry caatinga forests. Conspicu-
ously, C. pilifer var. lamellatus has lamellae six cells high, but
it occurs not in drier habitats but in rainforests. It can be
assumed that the lamellae also allow a better gas exchange in rain
forest habitats with higher humidity and higher tem- peratures.
2. Ventral hyalocysts and ventral stereids. In more than half of
the species of Campylopus the ventral stereids in the transverse
section of the costa of most Dicranaceae are replaced by ven- tral
hyalocysts. As shown by often narrower ad- axial cell walls, these
hyalocysts function for wa- ter storage. The size of the hyalocysts
varies between 14 and % of the leaf width. Species with lax
hyalocysts occur in wet habitats (as in many paramo species, e.g.,
C. jamesonii, C. cavifolius, and C. nivalis). Species of mesic
habitats have smaller hyalocysts with firm cell walls. In dry
habitats species show ventral stereids as protec- tion against
shrinking. This is best demonstrated
by the ventral stereids of C. pilifer ssp. galapa- gensis, which
occurs on dry lava flows, and C. pilifer ssp. pilifer which, with
ventral hyalocysts, occurs in less exposed habitats (Frahm,
1987b).
3. Dorsal stereids and dorsal substereids. Dorsal stereids occur
in bundles of 2-4 cells and function presumably for mechanical
fixation and perhaps also water transport. In some species these
stereids are replaced by one nonstereidal cell (which has a small
lumen and therefore is usually called substereidal). As in species
with large ventral hyalocysts instead of ventral stere- ids, these
species without dorsal stereids are also characteristic of wet
habitats, such as dripping cliffs or swamps.
Hyalocysts have usually been interpreted as water storage cells.
This is somewhat in contra- diction of the fact that species with
hyalocysts often occur in hygric habitats, where this func- tion is
not needed. Another possibility (in anal- ogy to Sphagnum) is that
they function in the uptake of nutrients in swampy habitats.
Recently Robinson (1985) added another theory. Robin- son observed
air bubbles in the hyalocysts of Leucobryaceae and Calymperaceae
from tropical lowland forests and supposed that these air bub- bles
can also function to allow a better gas ex- change for the
chlorocysts situated in the median of the costa, for chlorocysts
surrounded by cells filled with water would have a restricted gas
ex- change. The same may be the case for species of
Paraleucobryoideae with ventral and dorsal bands of hyalocysts and
also for some species of Cam- pylopus. However, in the
Paraleucobryoideae as well as in Campylopus, pores in the surface
of the leaves have not yet been observed as in Leu- cobryaceae and
Calymperaceae, indicating not only a structural but also a
functional difference.
Rhizoids
Rhizoids can originate from the basal parts of the stems and the
lower dorsal part of the costa. Only in Dicranodontium and
Atractylocarpus are rhizoids also borne on the ventral part of the
costa (Crundwell, 1979), showing the close re- lationship between
the two genera. Only stem- borne rhizoids are found in
Campylopodium (Crundwell, 1979) and Microcampylopus (as in
Dicranella and Microdus) showing in this (and other respects)
connection of these genera to the Dicranelloideae rather than to
the Campylopo-
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10 Flora Neotropica
dioideae. Thus leaf-borne rhizoids may be a good character of
the Campylopodioideae in a revised sense. They can be lacking,
scattered or form a dense tomentum. Since rhizoids function for an
external transport of water, low species (such as species of
Sphaerothecium, Campylopodium, Microcampylopus or Brothera) have
usually few or no rhizoids. Even in larger species this char- acter
seems to be controlled by the environment. It seems therefore to be
as unstable as the pres- ence of alar cells, which cooperate with
the rhi- zoids in the transport and uptake of water. A tomentum is
found especially in those species forming dense cushions such as
many paramo species. Sometimes the color of the tomentum has been
used for identification. However, rhi- zoids are generally reddish
in normal light and orange brown in transmitted light in older
parts by incorporation of phenolic compounds in the cell walls and
whitish in normal light or hyaline in transmitted light in younger,
outer parts. Thus a dense tomentum may look whitish as seen from
the outside but is reddish inside. Only the hyaline tips of the
rhizoids seem to resorb water.
The structure of the surface of rhizoids has been successfully
used for differentiation of spe- cies in some mosses but has been
studied only in detail for Campylopus (Frahm, 1983b). Rhi- zoids
are usually smooth but a few species with papillose rhizoid
surfaces have been found.
Recently rhizoid gemmae have been found in a species of
Campylopus from Europe (Arts, 1987) and in one species from the
neotropics. They may, however, have been overlooked, since such
gemmae were not expected in this genus.
Stems
The stems show an internal differentiation into an outer
cortical layer with firm, thickened cell walls, a median
parenchymatic tissue and a cen- tral stand of small, narrow,
elongate cells (Fig. 4).
Calyptrae The calyptrae are cucullate in all genera. This
concerns more or less ripe capsules. In young sporophytes the
capsule is fully covered by the calyptra which is symmetric at this
stage and not split. Indications of mitrate calyptrae for genera
such as Brothera in the literature probably de-
pend on such early stages of development. The calyptrae may be
ciliate or entire at base. This character seems to be fixed
genetically and has been used for differentiation of species in
Cam- pylopus but must be used with some caution, since in
Campylopus ciliate and non ciliate ca- lyptras have been found in
the same species. It can be supposed that in humid habitats the
tissue of the calyptra may grow on after separation from the
vaginula and thus form cilia. In dry habitats the calyptra may not
develop cilia or the cilia are broken off. Cilia are especially
long and con- spicuous in Campylopus subg. Thyanomitrion and subg.
Campylopidulum.
SPOROPHYTE
Sporophytes usually arise terminally from the gametophyte.
Pseudolateral insertion has been found only in a few species of
Campylopus, such as C. shawii and C. controversus.
Setae
The setae are comparable short. In Sphaero- thecium they are
only 3-4 mm long and im- mersed in the perichaetial leaves.
Notably, all three species of Sphaerothecium, found in Co- lombia,
South Africa and Sri Lanka, are known only from small ranges
covering a few square kilometers. In Microcampylopus the setae are
also only 2-6 mm long but not immersed in the leaves. In Campylopus
the setae are usually 8, rarely 12 mm long and in Bryohumbertia and
Atractylo- carpus the setae reach a maximum length of 15 mm. The
short length of the setae indicates an origin of the genera in open
habitats, where the capsules are exposed to the wind, and not in
forests or similar habitats, where a short seta would be a
disadvantage.
The setae show an interesting twist mecha- nism. They are
twisted in the dry state and uncoil when they are wetted even by
water vapor. Al- though this effect has been known for more than a
hundred years, the mechanism for this torsion was not known until
recently. Noticeable in all species with coiling setae, the outer
cortex of the setae has strong asymmetric thickenings. Recent SEM
and TEM studies (Frey & Frahm, 1987) have revealed that there
are groups of small pores 80 A in diameter in the primary and
secondary cell walls of the epidermis layer. Water or water
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Anatomy 11
^
''
-. ? : ' . '.
FIG. 4. Transverse sections of stems in different genera of
Campylopodioideae and Paraleucobryoideae. A. Pilopogon macrocarpus
(Allioni 8056, H-BR). B. Atractylocarpus longisetus (Pringle 10603,
NY). C. Microcam- pylopus curvisetus (Sartorius 60, BM). D.
Campylopus richardii (Griffin et al. 1035, FLAS). E.
Campylopodiella stenocarpa (Maslin s.n., NY). F. Campylopodium
medium (Steere 6831, MO).
vapor can pass through them and be absorbed by pectine in the
microfibrils of the incrassate tertiary cell walls. These
microfibrils, coiled in the dry state, enlarge, causing an
uncoiling move- ment of the setae. The setae are straight in some
genera (Atractylocarpus, Pilopogon, Paraleuco- bryum) but sinuose
in all other genera. This shape originates when the seta first
grows upwards and
then curves downwards. In this manner the young sporophyte
becomes situated between the peri- chaetial leaves, where the
capsule develops pro- tected against desiccation. When the capsule
is ripe the seta grows upward again, producing a second curve and
thus a sigmoid shape to the seta. In this way the calyptra is
frequently left between the perichaetial leaves. The sigmoid
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12 Flora Neotropica
shape of the seta causes wide movements of the capsule when the
seta is uncoiling. In these gen- era the setae are twisted
dextrorsely in the upper part but sinistrorsely in the lower part
which prevents the setae from being torn off by the uncoiling
movements.
Capsules The capsules are 1.5-2 mm long in the Cam-
pylopodioideae. They are globose (Sphaerothe- cium, Campylopus
subg. Campylopidulum), long cylindrical (Pilopogon,
Atractylocarpus), or ovoid to short-cylindrical, especially when
empty. They can be straight and symmetric or curved and asymmetric,
the latter often being strumose (Fig. 5). The color varies between
yellowish in young capsules to dark brown on old capsules. When
emptied, the capsules are furrowed and contract- ed below the
mouth. In the Paraleucobryoideae capsules are cylindrical. Seta
length and capsule orientation are important for spore dispersal.
Conspicuously cylindric capsules are correlated with long, erect,
nonsinuose setae, as in Atrac- tylocarpus and Pilopogon. Here the
spores are released by vibrations of the setae by wind. In genera
which have the sophisticated twist mech- anism combined with
sinuose setae, the spores are shed by spiral movements of the
setae. In Campylopus both symmetric, upright and asym- metric,
curved capsules are found. Species with conspicuously upright
capsules usually occur in open habitats, whereas those with curved
cap- sules grow in forests.
In the Paraleucobryoideae the capsules are al- ways erect,
shortly to longly cylindric, and 1.5 mm to 2.5 mm long.
The operculum is about half as long as the urn and obliquely
rostrate in most genera and longer in Bryohumbertia. It is usually
darker colored than the urn.
Stomata
Stomata at the base of the capsules are found in Campylopodium
(Campylopodioideae) and Paraleucobryum (Paraleucobryoideae,
although there are no stomata indicated in the literature),
conspicuously only in these representatives of different subgenera,
but not in closely related genera. They are cryptoporous in
Campylopo- dium but phaneroporous in Paraleucobryum.
Annulus
An annulus is present in the Paraleucobryoi- deae in Brothera
and in Campylopodiella steno- carpa. It is apparently lacking in
the Campylo- podioideae, although in Campylopus there are sometimes
indications of an annulus found in the literature.This seems,
however, to refer to an annulus which is visible microscopically as
dif- ferentiated cells but not dehiscent.
Peristome
The peristome consists of 16 teeth which are usually split to
half (or more) their length. Only in the two species ofPilopogon
subg. Thysanomi- triopsis and in the monotypic genus Brothera are
the peristome teeth not divided. There are two types of peristome
teeth: the so called dicranoid type consisting of elongate
triangular teeth, which is common in most genera, and another type
consisting of narrow, filiform teeth (Fig. 6). The abaxial surface
of the dicranoid peristome shows longitudinal striae, the adaxial
surface has trans- verse ribs, usually densely covered by papillae
(Fig. 7, except for Bryohumbertia). In the dry state the peristome
is closed because the inner transverse ribs, forming U-shaped
structures, are dried up and bent inwards. When moistened (fa-
cilitated by the papillae) the tension between these ribs is
lowered, the distances between these ribs are enlarged by
absorption of water vapor and the peristome teeth move outwards. By
this mech- anism spore dispersal is possible in moist con- ditions.
At the same time the setae uncoil, re- sulting in despiralizing
movements or, in genera with sinuose setae, resulting in wide
circular movements. Due to the moist condition when the spores are
released they are probably not dis- persed far. This has some
importance for these genera that are dioicous because female and
male spores must fall nearby to allow fertilization in the mature
plants. Filiform peristome teeth oc- cur in Campylopus subg.
Thysanomitrion and in Pilopogon. Both genera show strong
resemblance also in gametophytic characters, but are distin-
guished by sinuose setae in Thysanomitrion but straight setae in
Pilopogon (which shows that this character is perhaps overvalued).
Here the peri- stome teeth are longer, ending in slender, round
apices which are papillose. The broader basal part of the teeth
(lower 1/4) has the same structure
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Anatomy 13
< / / ft fI"/
A / I I B
B(B
A ; " i W V i U
fl
K
if- H
FIG. 5. Shape of capsules in different stages of development in
the genus Campylopus sect. Homalocarpus (A-D) and sect. Campylopus
(E-H). A. C. nivalis (Sharp 3043, TENN). B. C. areodictyon (Griffin
356, FLAS). C. C. argyrocaulon (Hegewald 9171, hb. Frahm). D. C.
occultus (Puiggari 331, H-BR). E. C. arctocarpus (Vital 4264, SP).
F. C. pauper (Lindig s.n., H-BR). G. C. chrysodictyon (=pauper)
(Lindig s.n., NY). H. C. concolor (Lindig s.n., NY).
as in the common dicranoid type. In addition to the opening
mechanism described above, the long apices of the peristome teeth
are twisted when in the dry state but uncoil when moistened (as
in the pottiaceous type of peristome). In both groups only the
one representative of Pilopogon in Africa and the only
representative of Thysano- mitrion in the subantarctic (which are
regarded
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14 Flora Neotropica
VAaz~~~~~~~~~~isi
11' O
or , o? "
'It,
n.y
FIG. 6. Types of peristomes in Campylopodioideae. A. Entire
peristome teeth in Pilopogon laevis (Lindig s.n., H-BR). B. Bifid
peristome teeth in Microcampylopus curvisetus (Sartorius 60,
BM).
as the most primitive species) have the normal dicranoid type of
peristome. It can thus be as- sumed that the species of Pilopogon
in South America developed after separation of the Gond- wana
continent, caused by changing ecological conditions stemming from
the uplift of the An- des, while Pilopogon africanus remained un-
changed in Africa. In this regard the neotropic type of peristome
would be the most advanced. The same can be assumed for
Thysanomitrion, in which species evolved from the present sub-
antarctic ancestor and extended to the tropics with a special
speciation in SE Asia.
Spores The spores are ca. 10-19 um in diameter in
most genera and are therefore best adapted for long distance
dispersal. Only in Campylopodium and Microcampylopus are they 18-24
Atm, ca. 21 Lm in Sphaerothecium and 19-34 um in Paraleu- cobryum.
In the numerous species of Campylo- pus and species of
Bryohumbertia and Pilopogon spore size is remarkably uniform at ca.
13 Am.
The spore ornamentation is not yet known by SEM studies for all
genera. To the extent that the genera have been studied, it varies
between near- ly smooth to finely or coarsely papillose in Cam-
pylopus to warty in Microcampylopus and Cam- pylopodium (Figs. 8,
9). This does permit separation of subgenera and sections in Cam-
pylopus (insofar as this can be generalized from the comparatively
few species which have been studied) and even species in
Microcampylopus and Campylopodium.
CYTOLOGY Chromosome numbers are known for only 18%
of the mosses, mainly for species of Japan, Eu- rope, North
America, India, Australia or Ant- arctica. Very little is known
about tropical moss- es. According to Fritsch (1982) there are no
counts for Atractylocarpus, Pilopogon, Sphaerothecium or
Bryohumbertia. For Campylopodium n = 13 + m and 35 + 1 are given,
but the count of the first species belongs to Microcampylopus after
a
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-
Cytology 15
. E . > ,~~~~~ / / '. ? ._, /.
. . / ,:.. '~./,~...
.% /,
t z,,~7
!? i> @
"' ~ ; c ,;t ;~, r fii
A- III' ' a , A /' , !
I~ ~ % i _ _? , 'i~J ' 'tf.'/X
, ~;r?
-[~~~~~~ . : 2 ' , / f' ~ a~IB / ,
?I , i". ~ , ~.
? ~ . z~ '~ z
_ \ - N ' ' .
FIG. 7. SEM pictures oflpenstomes. A, B. Bryvohumbertiafilifolia
(Frahm 1555, hb. Fralm). C. Campylopus
occultus (Ge 2, JE). D. Atractylocarpus longisetus (Pringle
10603, NY).'
__Xs~~ ?-?/ ;r hs w# S{ }
__ (?. ?r ' t ; i
S_;;li'g, ' tL'^'.
l~~~nii, _I?s _
~~~~~~~~~Ir j ! t r 'if: _=~~
_
?f
1 *e l - T
_;*,~~j~ t, jt. ?D -- ' _,,_.st1 i ' Si i'X
;~~~ -1 : , ^~~~~~~~~~~~~~~~~~~~~~~~- 1. A. _ hy+"~~. t 1F
_ : t~~~~ ~ ~ ~ ~ ~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ tt - < -
il < _ l~~"? ;0?
tM ~ ~ r Bb'je _ Ba n, L ocutu Ghr 5, J)D.Arcyoaps logseu (Pinl
1063 Y)
revision of the genera (Giese & Frahm, 1985a, 1985b) and the
second count concerns a species of Dicranella. This shows that
chromosome counts are highly dubious for genera which have not been
revised or are from species which have been erroneously identified,
which again con- cerns mostly tropical species. In the one species
of Dicranodontium studied cytologically, n = 11-
12 are found in different parts of the range. Chro- mosome
numbers in Campylopus are known from 14 species (=approx. 7% of the
actual number of species, Frahm, 1983b), and one of them is now
transferred to Bryohumbertia. None of these counts is from
neotropical material. This is part- ly due to methodological
difficulties. Only two of these counts were taken from mitosis, all
oth-
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16 Flora Neotropica
'. .
FIGs l s ( l 1 , N . B. FIG. 8. Spores ofCampylopodioideae. A
Atractylocarpusl 1ongisetus(Pringel 10603, NY). B.
Campylopodium
medium (Steere 6831, MO). C. Campylopus caroinae(Yital 1714,
SP). D. Microcampylopus curvisetus (Sartorius 60, BM).
ers from meiosis, which are more easily obtain- able. However,
only a few of the species of Cam- pylopus produce sporophytes
consistently and the sporophytes of numerous species are not even
known. The basic numbers are 10, 11, 12, 13 and 18. Chromosome
numbers of 10-14 are commonly regarded as basically diploid (New-
ton, 1984) and thus all species of Campylopus can be regarded as
diploid, two of them with n = 18 also triploid. Although most
counts are taken from one population only and not from different
populations, especially in species with transcontinental ranges,
the results presented are too similar to expect surprises in
additional re- sults. This is not different from most Dicranales in
which n = 13, 14 are found, probably poly- ploids of n = 7. In the
Paraleucobryoideae n = 12 is given for Brothera leana. For the
genus Campylopodiella n = 14 + m is reported based on one count in
one species and n = 12 or 14 for Paraleucobryum longifolium. As in
the Cam- pylopodioideae all counts fall into the same range of the
Dicranales.
CHEMISTRY Flavonoid patterns of several species of Cam-
pylopus (Frahm, 1983b), Pilopogon, Campylo- podium and
Microcampylopus (Frahm, unpubl.) have been studied. In Campylopus
different fla- vonoid patterns allow separation of subgenera and
sections. Surprisingly, in two species of Campylopus (C.
albidovirens, C. pittieri from the neotropics) no flavonoids have
been found. Both species vegetatively much resemble the genus
Paraleucobryum, which also has no flavonoids (Muller & Frahm,
1987) and seems to indicate a phylogenetic connection between these
two genera of different subfamilies. However, Leu- cobryum, a genus
with a similar anatomical structure of the costa, also has no
flavonoids (Hu- neck, 1983), although the genera may not be closely
related (Loeske, 1907). Other chemical constituents of the
Campylopodioideae and Par- aleucobryoideae have not been studied
very much. In Campylopus introflexus steroids such as campesterol
have been found as well as the
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Geography 17
_(* W** .fiC. i~Ia
I, 4L
FIG. 9. SEM photographs of spores of Campylopodioideae. A.
Campylopus flexuosus (Hakelier s. n., hb. Frahm). B. Campylopus
occultus (Gehrt 352, JE). C. Bryohumbertia filifnolia (Frahm 1555,
hb. Frahm). D. Atractylocarpus longnisetus (Pringle 10603, NY).
'
'~ ~ ~ ~~~P "'a .... '~~~~~~~~~~LI I? r
--3C_L~~~~~~~~~~~~~~~~~~~ "~~~~~~4~~~~,"~~ '74 ~ ~~f $;
L ~'l,. FI. 9 E ho orpsopoefCmylpdoda.A.Cmyou iexou (H k eir
s.n. hb. Fram) B Crnylpu cutu (Ght32 E.C rohmetaflfla(rhr 55
a.Fam.D
Atatyoaru lni s ts(ri n 100,N)
triterpenoid hop-22(29)-ene (Huneck, 1983), but these few
results have no systematic significance. In many species of
Campylopus, Dicranodon- tium, Bryohumbertia and Pilopogon, lipids
can be observed in the cells of the lamina and costa. This effect
is visible only in species with firm basal laminal cell walls and
not in those with hyaline, thin cell walls (and thus not in species
of Paraleucobryoideae). Tropical species have firm cell walls in
the lower part of the leaf, where- as subantarctic and andine
species have hyaline basal laminal cells. Since lipids function as
re- serve substances it may be supposed that these lipids function
for balancing the energy loss by
respiration which is especially critical for eco- logical
conditions of the tropics.
GEOGRAPHY
Range extent differs considerably in the genera of the
Campylopodioideae and Paraleucobryoi- deae. It is smallest in the
genus Sphaerothecium, in which all three species are known only
from a few records within a few square kilometers. In contrast, the
range of the genus Campylopus comprises nearly the whole world
between 65?S and 70?N latitude and an altitudinal range be- tween
sea level and 4800 m. This extreme dif-
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18 Flora Neotropica
ference is mainly due to different structural and ecological
adaptations, which are treated in de- tail in the chapters on
anatomy and ecology.
Pilopogon is represented in tropical Africa with one species, in
Central and South America with seven. Only one of these species
ranges widely through Central America, the Caribbean and to Brazil;
all other species are confined to larger or smaller parts of the
Andes (which can therefore be regarded as a centre of radiation of
this genus), either by geographical isolation (as in P. schilleri
from Chile) or habitat diversity (as in P. tiqui- payae or P.
macrocarpus).
Dicranodontium is a mainly holarctic genus. Only a few species
are found in the tropical mountains of South America, Africa and SE
Asia, probably derived from holarctic ancestors, since these
species are mostly confined to the northern parts of the tropics
and rarely cross the Equator.
Bryohumbertia is represented with one species each in the
neotropics, tropical Africa and SE Asia. All three species are
apparently very closely related, the taxa in Africa and SE Asia
being more closely related than either of these is with the
neotropic species.
Microcampylopus is also represented in the tropics with one
species each in the neotropics, Africa and SE Asia. The African
species occurs also in SE Asia.
Campylopodium comprises two species, one with a wide
circumpacific distribution from Ja- pan to New Zealand and Chile,
the other endem- ic to New Zealand and Tasmania.
Atractylocarpus comprises nine closely related species
worldwide. All species are confined to alpine habitats. There is
one species each in all mountain massifs of the world and thus no
over- lapping ranges. The ranges vary much in size, between
Eurasian in A. alpinus and endemic spe- cies, like A.
madagascariensis.
Paraleucobryum is again a holarctic genus comprising three
species of which one (P. enerve) goes down to Central America. Only
one taxon (P. longifolium ssp. brasiliense) occurs in the tropics
and is endemic to SE Brazil.
Brothera is monotypic and has a disjunct range between East Asia
and SE of North America and Mexico, probably as a relict of a
former amphi- oceanic range in the Tertiary.
Campylopodiella shows a similar disjunction, but at the generic
level, with one species in the Himalayas and two in Central and
northern South
America. The neotropical species are separated by a different
altitudinal range and have probably evolved from the same ancestor
in the course of the Andean folding.
Most species are found in subtropical, tropical montane or
tropical alpine regions and do not occur in the lowlands of
equatorial latitudes. Only a few species of the better adapted and
(according to the number of species) most successful genus,
Campylopus, can survive here. These species (C. surinamensis, C.
savannarum) are confined to open, light habitats such as sandy
shores of rivers or sandy soil in heath forests. This effect is
prob- ably caused by physiological problems. In ex- periments,
tropical montane species did not reach a sufficient net
photosynthesis under lowland conditions with high temperatures and
low light intensity (Frahm, 1987c, 1987d). Only taxa that are
physiologically specially adapted seem able to grow in the
understory of the equatorial rain- forest. A higher light intensity
in open habitats allows the species mentioned above to compen- sate
for the high rates of respiration in part. It remains an open
question why those species of Campylopus found in the Amazon
lowland occur only on sandy and not on lateritic soil.
In Campylopus all types of distribution, from tropical disjunct
species to endemic taxa, are found. There are only a few species
occurring throughout the tropics. If ranges cover South America,
Africa and Asia (as in C. pilifer or C. savannarum), the
distribution in Asia is confined to India and Sri Lanka. Such
species are replaced in SE Asia by vicariant species, which demon-
strates that isolation of SE Asia by continental drift happened
earlier than the isolation of India from Africa or Africa and South
America.
There are several phytogeographical relations to Africa. Several
species are disjunct between Africa and South America. Inasmuch as
they are either lowland species (Campylopus savanna- rum), montane
(C. flexuosus, C. fragilis), or al- pine species (C. nivalis, C.
incacorralis, Frahm, 1982b) and also species which produce spores
either frequently or extremely rarely, seems to indicate that both
long distance dispersal (es- pecially of fertile alpine species) as
well as sep- aration of populations by continental drift (of
sterile lowland species) can be considered as rea- sons for these
disjunctions. It highlights the fact that at least the lowland
species may be older than the separation of South America and
Africa
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Geography 19
at the end of the Mesozoic. Comparing the num- ber of species in
both continents, Africa has, with 50 species of Campylopus, fewer
species than South America, with 65 species. This is partly due to
a richer speciation of this genus in the Andes. Although the
isolated mountain massifs in Africa seem to support endemism by
isolation, this is not the case in Campylopus. In contrast, this
situation in Africa seemed to interrupt pos- sible migration routes
and caused small ranges of species. Air currents in the tropics
generally go from east to west (van Zanten 1983) and there- fore
the origin of the alpine species occurring in Africa and South
America should be African. This is difficult to imagine, since
these alpine species have apparently evolved from subant- arctic
ancestors and had a better pathway to the tropical mountains in
South America through the continuous Andes rather than, as in
Africa, by hopping from one mountain to the other.
The phytogeographical connection of species of Campylopus in
South America and Africa is also expressed by subspecies and
species pairs (Frahm, 1988). For example, C. julaceus and C.
trachyblepharon are both represented in SE Bra- zil and in SE
Africa by subspecies differing only in the height of the dorsal
lamellae of the costa or the presence of ventral hyalocysts or
stereids in the transverse section of the costa (Frahm, 1985a).
Both subspecies occur not only at the same latitude on the east
coasts of the respective continents, but also in the same habitats
of nu- trient poor sand near sea level. The same dis- junction
between SE Brazil and Malagasy is found in the hepatic genus
Bryopteris and the moss ge- nus Phyllogonium. A similar effect is
that of spe- cies pairs occurring in both continents as Cam-
pylopus sehnemii and C. controversus in South America and C.
cataractilis and C. stenopelma in South Africa (although there is
principally no difference since the differentiation between sub-
species and species pairs is surely problematical). Both species
pairs are so closely related that a common origin of both species
is most probable. It can be supposed that both species are derived
from subantarctic ancestors, which are still ex- tant (C.
incrassatus for C. sehnemii/cataractilis and C. purpureocaulis for
C. controversus/steno- pelma). After continental separation, both
spe- cies may have migrated northwards to the sub- tropical and
tropical regions and in this way have developed their own
characters.
Disjunctions between Central America and Asia are illustrated by
Campylopus japonicus (Mexico-Japan) and Brothera leana (East Asia-
SE North and Central America). This is a type of disjunction found
more frequently in other bryophytes as a result of a previous
circumpacific range in the Tertiary. The genus Campylopo- diella is
also disjunct between Asia and the neo- tropics with C. himalayana
and C. crenulata in the Himalayas and New Guinea and C. steno-
carpa and C. flagellacea in Central America and the Andes.
A circum-Tethyan range is found in Campy- lopus oerstedianus,
occurring in Costa Rica, Ja- maica, Georgia and again in scattered
localities in southern Europe. This indicates a Mesozoic age of
this species, the scattered present distri- bution being a result
of the lack of sporophytes and probably also unfavorable ecological
con- ditions.
A disjunction between North and South Amer- ica is found in
Campylopus carolinae which is found in the Cerrado regions of
Brazil and also in the alluvial coastal plains of Florida, Georgia
and the Carolinas. In both regions absolutely the same habitat is
occupied (white sand in often burned vegetation in which the minute
plants are buried). Campylopus surinamensis also grows on white
sand and shows a similar distribution pattern but occurs also in
between in the Amazon lowland. Campylopus angustiretis is disjunct
be- tween SE Brazil and the Caribbean and is found in the same
vegetation types as the previous spe- cies, but in swampy places.
All three species can be regarded as relicts of a former continuous
range of a dry vegetation type linking Brazil, the Ca- ribbean and
the SE of North America. In con- trast, the occurrence of C.
trachyblepharon (which grows in coastal sand and is mainly
distributed in SE Brazil) in N Brazil and the Bermudas is
interpreted rather as a result of dispersal by birds.
Only few species show pan-neotropic ranges and are found from
Central America to Brazil (but usually with the exception of the
Amazon lowland). This concerns Microcampylopus curvi- setus,
Pilopogon gracilis, Bryohumbertiafilifolia, Campylopus
lamellinervis and C. subcuspidatus (except for the Andes), C.
richardii, and C. arc- tocarpus and in addition the lowland and
mon- tane species with an African-South American disjunction such
as Campylopus fragilis, C. flex- uosus, C. savannarum, and C.
pilifer. Also, Bryo-
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20 Flora Neotropica
humbertia filifolia and Campylopus arctocarpus have close
relations to Africa, as indicated by the fact that B. filifolia is
replaced in Africa by a closely related species, B.
metzlerelloides, and C. arctocarpus is replaced by a vicariant
race, ssp. madecassus.
Within South America disjunctions can be ob- served between the
Andes and SE Brazil. There are several categories of species:
species which show no differences between the populations
(Atractylocarpus longisetus, Campylopus cuspi- datus, C.
heterostachys, C. jamesonii, C. densi- coma, C. reflexisetus);
populations, as in Pilo- pogon gracilis, in which differences can
be stated numerically, but which, however, overlap and do not allow
separation of these populations tax- onomically (Frahm, 1983a);
subspecies, as in Campylopus fragilis subsp. fragilis in the Andes
and subsp. fragiliformis in SE Brazil; or geo- graphical vicariant
species such as Atractylocar- pus brasiliensis and A. longisetus or
A. nanus. These disjunctions can be explained either by long
distance dispersal or as relicts of a formerly closed range that
included the Andes and the SE Brazilian mountains in a presumably
cooler cli- matic period.
Extensions of boreal ranges to Central Amer- ica, rarely to
South America, are found only in Paraleucobryum enerve and
Dicranodontium denudatum.
Disjunctions between Central America and SE North America are
demonstrated by Brothera leana and Campylopus tallulensis.
Campylopus shawii is disjunct in the Carib- bean, the Azores and
the British Isles.
Several species are endemic to SE Brazil, for example Campylopus
cryptopodioides, C. di- chrostis, C. gemmatus, C. julicaulis, C.
uleanus and C. viridatus. Some Campylopus species (C. aemulans, C.
julaceus, C. griseus and C. occultus) are also found on or proceed
to the slopes of the Andes in N Argentina and S Bolivia.
Campylopus gardneri, C. gastro-alaris and C. widgrenii are
endemic to the arid parts of S and NE Brazil.
There are numerous species which are con- fined to the Andes and
which have probably evolved in consequence of the uplift of these
mountains at the end of Tertiary. This makes the Andes the region
with the highest number of species in the world for Campylopus and
Pilo- pogon. According to the humidity gradient in the
Andes from the Equator north and south the ranges of these
species are very different. The widest ranges from Mexico to
Bolivia (rarely to northern Argentina) are found in Campylopus
albidovirens, C. anderssonii, C. concolor, C. ob- longus, C.
pittieri, C. sharpii and C. zygodonti- carpus. Species confined to
the region between Costa Rica and Peru or northern Bolivia are
Campylopus asperifolius, C. cavifolius, C. hual- lagensis, C.
trivialis and Pilopogon laevis. Only found between Venezuela and
Bolivia (and often confined to even smaller ranges such as Colom-
bia to Peru or Colombia and Venezuela) and not in Central America
are Atractylocarpus nanus, Campylopus amboroensis, C. areodictyon,
C. ar- gyrocaulon, C. bryotropii, C. capitulatus, C. clee- fii, C.
edithae, C. incertus, C. jugorum, C. lon- gicellularis, C. luteus,
C. perexilis, C. subjugorum, C. trichophylloides, Pilopogon
peruvianus and P. macrocarpus. These are predominantly alpine
species. Some species have even smaller ranges, e.g., confined to
Bolivia (P. tiquipayae) or Co- lombia (Sphaerothecium phascoideum).
The only species confined to Central America seems to be
Dicranodontium meridionale, but this genus has not yet been
monographed and therefore any phytogeographical interpretations are
doubtful.
A phytogeographical discussion for the species of Campylopus and
Bryohumbertia from the Ro- raima massif is given by Frahm and
Gradstein (1987).
Campylopus cygneus and C. cubensis are con- fined to the
Caribbean, the latter is also found in the surrounding parts of the
continent in Cen- tral and northern South America, perhaps as a
result of secondary spreading.
ORIGIN AND EVOLUTION Because of the lack of any fossils from
either
subfamily, only speculations can be given de- rived from
interpretation of the present ranges of species and genera.
Atractylocarpus is represented in nearly all mountain massifs of
the world, each with a single species. Since these mountains are
predomi- nantly of Tertiary Age, speciation within this ge- nus has
happened presumably only during the last 50 million years.
Atractylocarpus is mainly tropical and alpine in distribution. It
is closely related to Dicranodontium, which is boreal and montane.
The anatomical differences concern
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Origin and Evolution21
mainly the sinuose or erect setae. A circumboreal distribution
can go back to a Laurasian origin and thus it can be assumed that
Dicranodontium is older than Atractylocarpus and that the latter
has evolved from Dicranodontium by occupying new niches in alpine
regions and has differenti- ated into several species on isolated
mountain massifs.
In Campylopus it is notable that there are 15 (revised from 60
described) species in the sub- antarctic but only one in the
subarctic. More- over, (except for one) only species with hyaline
thin walled basal laminal cells occur in the sub- antarctic, and
the most primitive representative of the subgenus Thysanomitrion
also occurs there. So it can be assumed that this genus evolved in
the southern part of the Gondwana continent. Presumably, a rich
speciation took place (1) by isolation caused by continental drift,
(2) by spreading northwards in the continents under more favorable
climatic conditions, which were xeric in the preceding Mesozoic,
(3) by adapta- tion to new habitats in savannas and rainforests and
(4) by speciation in new mountain systems. For several groups of
species, pathways can be constructed illustrating these mechanisms
(Frahm, 1988). The existence of a circumtethyan relict (a
conspicuously dry-adapted species with hairpoints) indicates that
representatives of this genus were also present at the northern
part of the Gondwana continent.
As shown by bud-like perichaetia on appressed foliate stalks and
a different type of peristome, found also in the youngest species
of Pilopogon and in certain species of the subg. Thysanomitri- on,
(especially those occurring in SE Asia), the subg. Thysanomitrion
may represent the youn- gest branch of evolution in this genus.
The close relationship between Campylopus and Dicranodontium
leads to the suspicion that both genera (one in Gondwana, the other
in Laurasia) have a common ancestor. Nearly all species of
Dicranodontium can be distinguished from certain species of
Campylopus only by elon- gate upper laminal cells. In contrast to
Campy- lopus, Dicranodontium has never developed the large variety
of different structures of the costa. It therefore has remained
conservative and less flexible. Not able to adapt to different new
habi- tats, the genus was not able to participate in an enormous
speciation as was Campylopus. There- fore it remained confined to
its former range and
did not spread substantially into the tropics. In a little known
bryofloristic paper on the Austrian Alps, Loeske (1910) discussed
relationships be- tween genera of Dicranaceae. Based on the simi-
larities in the structure of the costa and the lami- na with
Ditrichum, Loeske derived Campylopus and Dicranodontium from
Ditrichaceae. Para- leucobryum belongs, according to Loeske, to the
same evolutionary line. For that reason Loeske proposed to separate
Campylopus, Dicranodon- tium and perhaps also Paraleucobryum from
the Dicranaceae and to establish a new family, Cam-
pylopodaceae.
Pilopogon also resembles certain species of Campylopus and can
be distinguished only by the straight seta and the long
perichaetial leaves. Six of the seven species occur in the
Neotropics, five of them exclusively in the Andes. As indi- cated
by the dicranoid type of the peristome in the only African species
and the advanced type of peristome in the neotropical species, the
genus originated in the Mesozoic before the split of the Gondwana
continent but further evolved later in the Andes.
Bryohumbertia is again closely related to Cam- pylopus,
differing by longer setae, a longer oper- culum and smooth
peristome teeth. Three spe- cies are distinguished worldwide, one
in each of the main tropical regions. The differences be- tween
these species are so small that certain small specimens can hardly
be referred to one or the other of these species, whereas some
large growth forms are confined to the neotropics. This close
relationship indicates a common origin and a recent differentiation
after the split of the con- tinents which may have not yet reached
a sep- aration into fully separate species.
The three species of Spaherothecium found in Colombia, South
Africa and Sri Lanka also show only small differences. The nearly
worldwide dis- tribution indicates an older age for the genus than
Bryohumbertia, with a late or post Mesozoic spe- ciation caused by
isolation. The small ranges of all these species indicate that the
present ecologi- cal conditions are not best for these species.
Since these species grow on bare soil and not in shel- tered
habitats, it may be speculated that these species (two of which are
known only from the type collections made 130 years ago, a third
known from only halfa dozen collections) cannot survive in such
small populations and may be extinct in the future, if not now.
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22 Flora Neotropica
Microcampylopus and Campylopodium differ mainly in the
ornamentation of the spores and the presence or absence of stomata
in the neck of the capsules. Consequently, both genera have a
relation similar to that of Dicranella (stomata absent) and
Anisothecium (stomata present), which are often united. A common
origin for both genera can be assumed, perhaps derived from
Anisothecium by development of the twist- ed and sinuose seta of
the Campylopus-type or by sharing the same ancestor with Dicranella
and Anisothecium. Microcampylopus is distributed pantropically,
with one species each in South America, Africa and SE Asia. These
species probably evolved after the separation of the con- tinents
and, because of their close relationship (the differences concern
only length/width of the capsule and the spore ornamentation), are
de- scendants of a Mesozoic ancestor. Campylopo- dium is SE Asian
in distribution, with two species (the occurrence of C. medium in
Chile is inter- preted as a Pacific extension of this range), and
therefore might have developed from Microcam- pylopus in this
region, or is older, with formerly vicariant species in other parts
of the tropics ex- tinct. A third possibility might be that the
Chil- ean and New Zealand occurrences are relicts of a
gondwanalandic range and the occurrence of C. medium in SE Asia is
a secondary extension.
ECOLOGY
SUBSTRATE
Most species of Campylopodioideae and Para- leucobryoideae grow
on soil, rocks, decaying wood or tree bases. This is true for all
genera except Campylopus and Pilopogon. Only a few species of the
latter genera, occurring in the An- des and the mountains of SE
Brazil, are epi- phytes. This supports the hypothesis of a Gon-
wanalandic origin and migration to the tropics, where only a few
taxa adapted to this new habi- tat. Within the neotropics, only one
Pilopogon species, P. longirostratus, is found as epiphyte. In
Campylopus only a few species such as C. asperifolius occur on tree
trunks or bamboo nodes. (Species growing also on stems of tree
ferns can- not be taken into account here since they are not true
epiphytes.) Only one species, Campylopus huallagensis var.
weberbaueri from the Andes, has become a branch epiphyte.
For an unknown reason all species of Paraleu-
cobryoideae and Campylopodioideae (as most Dicranaceae) are
strictly acidophytic and found only on substrates with a pH
-
Ecology23
ten pitted basal cell walls, which function for water storage
(Biebl, 1964).
Resistance to Water Loss
Growth form plays an important role for re- sistance to water
loss. Species of exposed habitats show dense tufts or cushions (as
in high andine species such as Paraleucobryum enerve, Atrac-
tylocarpus ssp., Campylopus nivalis, C. cavifoli- us, C.
areodictyon, C. edithae, etc. The same con- cerns subantarctic
species.
As in many other acrocarpous mosses a num- ber of species of
Campylopus have excurrent cos- tae forming hyaline hairpoints,
functioning as protection against strong radiation and desicca-
tion. In some species these hairpoints vary de- pending on the
habitat, as in Campylopus sa- vannarum with a concolorous excurrent
costa in rainforest habitats but a distinct hyaline excur- rent
costa in the "bartletti"' expression of dry cerrado habitats.
UPTAKE OF WATER AND NUTRIENTS
The anatomies of Paraleucobryoideae and Campylopodioideae show
adaptions to a less de- veloped internal and well developed
external wa- ter conduction. A structure supporting endohy- dric
water supply is the presence of a central stand in the stem.
Ectohydric features are easily wetted surfaces of leaves which
become turges- cent rapidly, no water repellent leaf surfaces, fre-
quent presence of a rhizoid tomentum and hy- aline leaf bases.
However, there are no leaf papillae developed to spread water
easily over the leaf surface; all species have totally smooth
leaves.
SEXUAL REPRODUCTION
Sexual reproduction plays a different role in the genera treated
here. Species of Microcam- pylopus and Campylopodium are nearly
always found with sporophytes. In this respect these gen- era
resemble Dicranella, to which they ultimately may be found more
closely related than to the Campylopodioideae. For Sphaerothecium
the rate of fertility cannot be estimated since the species are
known from only a few collections. It can be assumed that specimens
have been collected only with sporophytes, because the species can
almost not be distinguished from other genera without
capsules. In Brothera there are numerous collec- tions of
fertile material from its Asian range. However, in North and
Central America the spe- cies is found always sterile. In the
neotropic spe- cies of Campylopodiella, C. flagellacea is nearly
always sterile and has been found with sporo- phytes only once, but
in contrast, C. stenocarpa is found usually fertile. Only a small
number of species of Campylopus produce sporophytes fre- quently.
In many species sporophytes are found only rarely, and again in
many species no spo- rophytes are known. This is remarkable, inas-
much as Campylopus has developed this special turn and twist
mechanism of the sporophytes for spore dispersal, which is,
however, apparently not necessarily needed. In contrast to all
other genera treated here, some species of Campylopus produce
several sporophytes in one perichae- tium, usually 3-7. This is
especially character- istic for colonists such as C. introflexus,
C. ri- chardii or C. occultus. But even closely related or
geographically vicariant species can differ in spore production,
like C. introflexus, met fre- quently with sporophytes, versus C.
pilifer, which is rarely found with sporophytes. Dry-adapted
species produce sporophytes more rarely than species of wet
habitats, which apparently reflects better conditions for
fertilization in wet habitats and better vegetative propagation in
dry habitats.
Generally, species producing sporophytes have larger ranges.
This is especially true of species with large disjunctions, such as
between South America and Africa. Species in which sporo- phytes
are not known have either small ranges or are known from few
localities which also may be very scattered. An example is
Campylopus oerstedianus, known from less than a dozen rec- ords in
Costa Rica, Georgia and SW Europe.
The number of spores per capsule is not known in even a single
genus. However, the spore size is about the same in all genera,
with the exception of Microcampylopus and Campylopodium, which have
spores of 18-24 ,um diameter and Sphaero- thecium with spores 21 ,m
in diameter. There- fore, the size and number of capsules may give
an impression of the fertility of the genera.
The duration for the sporophyte development is not known for
tropical species. In temperate regions all genera show two growth
periods a year, each with one sporophyte generation. The sporophyte
development thus takes less than 6 months. The fertility in general
seems to be high- er in temperate and subtropical regions than
in
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24 Flora Neotropica
the innertropics. This may depend on the pho- toperiod in the
sense that bryophytes usually re- quire long days for the
development of sex or- gans.
VEGETATIVE REPRODUCTION
The total lack or rareness of sporophytes in many species shows
that there exist effective methods for vegetative propagation.
The production of organs for vegetative prop- agation is usually
seasonal and happens during a dry season, allowing a dispersal by
wind, and a regrowth in the next humid season. Some pop- ulations
produce propagules always, others nev- er. Plants without
propagules show optimal growth, the others not. Therefore,
vegetative propagation may indicate ecological stress.
Although there are several different methods of vegetative
propagation, a given method is usu- ally but not entirely confined
to certain taxa. For example, brood leaves are characteristic for
C. fragilis and microphyllous branches for C. flex- uosus. However,
there have also been found (but extremely rarely) microphyllous
branches in C. fragilis and brood leaves in C. flexuosus. This
indicates that while all species may have the same faculties for
all methods of vegetative propaga- tion, they are, however, used
differently.
Several species can switch between vegetative and generative
propagation, which is a most suc- cessful response to balance
alterations of habi- tats.
SYSTEMATIC TREATMENT
CAMPYLOPODIOIDEAE
Plants small, from a few mm to 15 cm high, yellowish green,
light to dark green or olive to
almost blackish, in loose tufts. Stems erect, rarely branched,
often tomentose in the lower part, co- mose at tips or not so,
rarely verticillate foliate. Dioicous. Perichaetia terminal, rarely
pseudo- lateral, surrounded by comose leaves; perichae- tial leaves
with broad sheathing base, abruptly contracted to subulae. Stem
leaves lanceolate, erect spreading to appressed, sometimes homo-
mallous or straight, ending in a fine denticulate, serrate or
smooth, sometimes hyaline tip. Costae broad, filling 1/3 to 3/ of
the leaf width, excurrent or nearly so, in transverse section with
a median row of deuter cells, dorsal layers of a (sub)stereidal
band and an epidermal layer and ventrally a sin- gle or
multilayerred stereid band or a single row ofhyalocysts, the
abaxial surface smooth, ribbed or lamellose; alar cells lacking,
more or less de- veloped or conspicuous, inflated or auriculate,
reddish or hyaline; basal la