*COMMENT ~ Character notes. 
 
*CHARACTER NOTES 
#1. From Smith (2004). In mosses, as in many other groups of organisms
in which common names do not exist, they have been invented
to satisfy bureaucratic regulations for conservation-related publications.
#2. ~ (alternatively) is here used to indicate sometimes not
unreasonably included in or reduced to.
#4. \i{}Acrocarpous\i0{}: of mosses in which the archegoniate
inflorescences, and hence the sporophytes (setae and capsules), terminate
main vegetative stems and/or branches. Acrocarps are usually relatively
short-stemmed, unbranched or only sparingly branched, never regularly
pinnately branched, and are usually erect or ascending in habit. Most
are either cushion-formers, or form turf like the pile of a carpet.
\par{}\sb50{}\i{}Pleurocarpous\i0{}: of mosses in which the archegoniate
inflorescences, and hence the sporophytes (setae and capsules), develop
laterally on specialized, dwarf, lateral branches or branchlets usually
bearing only perichaetial leaves. Nearly all pleurocarps are freely
branched, often pinnately so, and while diverse in habit their
relatively long, frequently prostrate or ascending secondary branches
often form dense, intricate mats or wefts.
\par{}\sb50{}\i{}Cladocarpous\i0{}: applied to rare, somewhat
intermediate forms in which the sporophytes (setae and capsules)
terminate short lateral branches. \par{}\sb50{}The
pleurocarpous/acrocarpous distinction is generally readily made, but note
that in some mosses, the originally terminal perichaetia may come to
appear lateral, being \i{}subsequently\i0{} overtopped by innovations
from beneath. 
#6. Multistate characters in which differences between some states seem
insufficiently clear-cut are best approached by selecting all the states
you feel MIGHT fit your specimen. Such characters can be very useful,
even if you use them only to eliminate one or two states that obviously
do not apply. 
#9. Estimates of plant sizes are obviously useful for identification, 
even if only to distinguish the relatively large from the minute. 
In order to utilize them, however, it is essential to record complete ranges.   
The ranges given here have often been deduced from species descriptions 
expressed in the form  .... plants to \i{}x\i0{} mm high, and in such cases, 
the lower limits are mere guesses. They have been  
deliberately set low, but the character is not as reliable as it 
ought be, and should be used with this in mind.


#13. \i{}Paraphyllia\i0{}: minute branched or unbranched filaments or
leaf-like structures borne on stems, among the leaves (see
\i{}pseudoparaphyllia\i0{}). 
#14. \i{}Pseudoparaphyllia\i0{}: minute branched or unbranched filaments
or leaf-like structures, resembling \i{}paraphyllia\i0{} (q.v.) but
confined to the bases of branches and branch primordia. 
#22. \i{}Sphagnoid\i0{}: In \i{}Sphagnum\i0{}, all the leaves are single
layered. The stem leaves are relatively simple, usually flatter and
tongue-shaped, and are composed entirely of hyaline cells with
relatively small pores. The usually concave and pointed branch leaves
are composed of large, empty, hyaline cells interspersed in a network of
very narrow, green assimilatory cells. The former, the walls of which
exhibit spiral thickenings and large, rounded pores, endow the living
and dead tissues with their remarkable capacity for absorbing and
retaining water. See illustrations. \par{}\sb50{}\i{}Leucobryoid\i0{}: In
\i{}Leucobryum\i0{}, the leaves are three or more layered, with a
median, open network of long and narrow chlorophyllous cells, sandwiched
between layers of much larger, empty, hyaline cells. The latter are
interconnected by conspicuous pores, and some have openings to the
outside, endowing the leaves with a sponge-like capacity to absorb and
retain water. They are analogous with branch leaves of the unrelated
\i{}Sphagnum\i0{}, but lack the spiral wall thickenings characteristic
of them. See illustrations. 
#23:25-32:34-45:47-52:54-56. Descriptions of leaves apply to typical,
fully developed, vegetative leaves, such as are generally found around
the middle of the stems, and sampling for pursuing identifications
should be conducted with this in mind. Proximal (basal) leaves on stems
and branches are often small or otherwise atypical, and should be
avoided, as should the branch leaves of those pleurocarpous mosses in
which they are evidently smaller and less well developed than the stem
leaves. Where necessary, the distinction must also be made between the
vegetative leaves and the bracts (perichaetial leaves) associated with
the reproductive structures, which in some but by no means all mosses
assume specialized forms. 
#24. Multistate characters in which differences between some states seem
insufficiently clear-cut are best approached by selecting all the states
you feel MIGHT fit your specimen. Such characters can be very useful,
even if you use them only to eliminate one or two states that obviously
do not apply. \par{}\sb50{}Descriptions of leaves apply to typical, fully
developed, vegetative leaves, such as are generally found around the
middle of the stems, and sampling for pursuing identifications should be
conducted with this in mind. Proximal (basal) leaves on stems and
branches are often small or otherwise atypical, and should be avoided,
as should the branch leaves of those pleurocarpous mosses in which they
are evidently smaller and less well developed than the stem leaves.
Where necessary, the distinction must also be made between the
vegetative leaves and the bracts (perichaetial leaves) associated with
the reproductive structures, which in some but by no means all mosses
assume specialized forms. 
#33. Dixons text regularly makes the distinction between states 2 and
3, but his illustrations do not always conform. See (e.g.)
\i{}Timmia\i0{}, page 310 and Tab. XXXVIII. \par{}\sb50{}Descriptions of
leaves apply to typical, fully developed, vegetative leaves, such as are
generally found around the middle of the stems, and sampling for
pursuing identifications should be conducted with this in mind. Proximal
(basal) leaves on stems and branches are often small or otherwise
atypical, and should be avoided, as should the branch leaves of those
pleurocarpous mosses in which they are evidently smaller and less well
developed than the stem leaves. Where necessary, the distinction must
also be made between the vegetative leaves and the bracts (perichaetial
leaves) associated with the reproductive structures, which in some but
by no means all mosses assume specialized forms. 
#46. Multistate characters in which differences between some states seem
insufficiently clear-cut are best approached by selecting all the states
you feel MIGHT fit your specimen. Such characters can be very useful,
even if you use them only to eliminate one or two states that obviously
do not apply. \par{}\sb50{}Descriptions of leaves apply to typical, fully
developed, vegetative leaves, such as are generally found around the
middle of the stems, and sampling for pursuing identifications should be
conducted with this in mind. Proximal (basal) leaves on stems and
branches are often small or otherwise atypical, and should be avoided,
as should the branch leaves of those pleurocarpous mosses in which they
are evidently smaller and less well developed than the stem leaves.
Where necessary, the distinction must also be made between the
vegetative leaves and the bracts (perichaetial leaves) associated with
the reproductive structures, which in some but by no means all mosses
assume specialized forms. 
#53. Multistate characters in which differences between some states seem
insufficiently clear-cut are best approached by selecting all the states
you feel MIGHT fit your specimen. Such characters can be very useful,
even if you use them only to eliminate one or two states that obviously
do not apply. \par{}\sb50{}Descriptions of leaves apply to typical, fully
developed, vegetative leaves, such as are generally found around the
middle of the stems, and sampling for pursuing identifications should be
conducted with this in mind. Proximal (basal) leaves on stems and
branches are often small or otherwise atypical, and should be avoided,
as should the branch leaves of those pleurocarpous mosses in which they
are evidently smaller and less well developed than the stem leaves.
Where necessary, the distinction must also be made between the
vegetative leaves and the bracts (perichaetial leaves) associated with
the reproductive structures, which in some but by no means all mosses
assume specialized forms. 
#59. \i{}Paraphyses\i0{}: uniseriate hairs (trichomes), which sometimes
occur mixed with the antheridia and archegonia. 
#60-61. \i{}Gemmae\i0{}: small, vegetative propagules (buds), which in
some mosses are produced on rhizoids, in leaf axils, on stem or leaf
surfaces, or on special structures. 
#64. Multistate characters in which differences between some states seem
insufficiently clear-cut are best approached by selecting all the states
you feel MIGHT fit your specimen. Such characters can be very useful,
even if you use them only to eliminate one or two states that obviously
do not apply. 
#68. Multistate characters in which differences between some states seem
insufficiently clear-cut are best approached by selecting all the states
you feel MIGHT fit your specimen. Such characters can be very useful,
even if you use them only to eliminate one or two states that obviously
do not apply. 
#71. \i{}Apophysis\i0{}: the more or less solid part of the moss capsule
below the spore sac, distal to and adjoining the seta. 
#74. \i{}Annulus\i0{}: a specialized, usually separable and often very
elastic ring or rings of cells between the mouth of a capsule and its
lid, associated with dehiscence of the latter. The descriptive data are
unsatisfactory, because none of the works seen specify \i{}absence\i0{}
of an annulus or give structural details. 
#75-79. \i{}Calyptra\i0{}: a thin veil or hood developed from the
(venter of) the moss archegonium, which covers the young capsule and at
least the lid of older capsules. 
#80. \i{}Cleistocarpous\i0{}: of capsules from which spores emerge by
rupture or decay of the capsule wall, instead of through dehiscence via
valves or a lid. 
#82-92:101. \i{}Peristome\i0{}: a single or double ring of teeth,
revealed at the mouth of typical moss capsules when the lid is shed. In
forms with a single peristome ring (haplolepideous), this is considered
usually to be homologous with the inner peristome ring of those with two
rings (diplolepideous). Peristomes show spectacular hygroscopic
movements associated with spore release, and the abundant variations in
structural details have long intrigued taxonomists. \par{}\sb50{}
Cleistocarpous capsules (q.v.) and those dehiscing via longitudinal
slits lack a peristome. \i{}Gymnostomous\i0{} capsules, which dehisce
via a lid but lack a peristome, are rare. 
#93. In the Bryopsida subclass Dicranidae (Haplolepideae), the peristome
teeth are proximally composed of two layers of plates. In the outer of
these, a single series of plates occupies the full width of the tooth,
but the \i{}inner\i0{} layer comprises two series of plates, aligned so
that the interior view of the tooth presents a fine dividing line
(stria) down its centre. In the other subclasses of Bryopsida
(Diplolepideae), when teeth are present, each also consists of two
layers of plates, but with the \i{}outer\i0{} layer comprising two
series divided by a vertical line, and the inner consisting of a single
series occupying the full width of the tooth. Thus, the tooth exhibits a
dividing line down its centre only in \i{}external\i0{} view.
\par{}\sb50{}In forms with a single peristome ring (Haplolepideae), this
is considered usually to be homologous with the inner peristome ring of
those with two rings (Diplolepideae). 
#104. Multistate characters in which differences between some states
seem insufficiently clear-cut are best approached by selecting all the
states you feel MIGHT fit your specimen. Such characters can be very
useful, even if you use them only to eliminate one or two states that
obviously do not apply. 
#111. Absence of data for this character implies that the references
consulted either provide no information for any of the species, or
inform on so small a proportion of the species that it is
uninterpretable at family level. The families left unrecorded may include
both calcicoles and calcifuges, as well as mosses confined to more or
less neutral substrates and others known to be found on both acid and
akaline substrates. It appears at first sight that many moss species
have restricted pH tolerances, with those confined to acid environments
outnumbered by the others; but reliable interpretation is complicated,
not only by the fact that siliceous rocks can incorporate calcareous
material, but also by the numerous species which, though characteristic
of chalk and limestone districts, grow on bark and on decaying wood
(i.e., on presumably acid substrates?). In any case, most of the larger
genera (and consequently all the large families) seem to be variable
regarding pH ranges. 
#120. The data have been compiled from the summaries in Smiths species
descriptions, and the extrapolated family distributions will sometimes
be too wide. Most of the moss families (unlike many of the species and
genera) seem to be represented more or less throughout Britain and
Ireland. \par{}\sb50{}Multistate characters in which differences between
some states seem insufficiently clear-cut are best approached by
selecting all the states you feel MIGHT fit your specimen. Such
characters can be very useful, even if you use them only to eliminate
one or two states that obviously do not apply. 
#124. Included for the purpose of tracking classificatory changes. 
 
