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BFNA Title: Orthodontiaceae |
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41.
ORTHODONTIACEAE Goffinet Patricia M. Eckel Plants small, in loose tufts
or scattered individuals, acrocarpous, pseudo-pleurocarpous (reproductive
structures on lateral innovations). Stems
10--17 mm, erect, in section with or without a central strand, epidermis
not differentiated. Leaves erect-spreading,
lanceolate, linear-lanceolate to setaceous from an undifferentiated base,
narrowed at the insertion; costa 1/3--1/5\x the leaf width, ending before the
apex to percurrent, in section undifferentiated or with a central stereid band;
margins 1-stratose, entire but denticulate in the apex; laminal cells linear,
smooth, with firm walls, becoming larger, lax, thin-walled, short-rectangular
to subquadrate near the insertion, cells at insertion red-brown in one or two
rows. Specialized asexual reproduction
frequent, by filamentous, 1-seriate, reddish brown propagula in the axils of
the leaves. Sexual condition autoicous
or paroicous, archegonia scattered distally on the stem, antheridia naked
among the perichaetial leaves or in lateral stalked perigonial buds below the
perichaetia, or both, leaves acute, ovate-lanceolate, ca. 1/5\x cauline leaf
length or less; perichaetial leaves scarcely differentiated. Seta elongate, greatly exceeding
capsule length. Capsule erect, ovoid
to subcylindric to oblong-pyriform, irregularly longitudinally wrinkled to
somewhat furrowed when dry, tapering to a neck up to 1/3\x capsule length;
exothecial cells evenly thin-walled, long- to short-rectangular; annulus absent
or rudimentary, persistent in 2--3
rows, adherent to the capsule mouth after dehiscence; operculum conic,
obliquely short- to long-rostrate; peristome diplolepideous-alternate, of 16
teeth; exostome pale yellow-brown, inserted somewhat below the capsule mouth,
narrowly lanceolate from a somewhat broader to broader base, scarcely
trabeculate, smooth or finely papillose, median fissural line present; endostome
segments undivided, hyaline to pale yellow, smooth to finely papillose, somewhat
reduced, as long as to shorter than the exostome, with or lacking the median
line, endostomial basal membrane short
or absent, endostome smooth or lightly papillose; cilia absent. Calyptra fugacious, cucullate,
smooth, naked. Spores (11--)16--18(--20)
\um, spherical, densely and finely to coarsely papillose. Genera
4 (1 in the flora): tropical-temperate worldwide. The
placement of the Orthodontiaceae is currently undergoing rapid revision.
Goffinet et al. (2008) placed the family in the order Rhizogoniales together
with the Rhizogoniaceae and Aulacomniaceae. This is quite different and
distant from the order Bryales with which the family has traditionally been
associated. W. Frey (2009) more recently recognized the family in the order
Orthodontiales, and segregated the other two families to their own orders,
Aulacomniales and Rhizogoniales. Orthodontium
was elevated to family status by W. R. Buck and B. Goffinet (2000). The
genus was, however, retained within the family Bryaceae by B. H. Allen (2002)
who adopted a broader generic view of that large and complex family. The Orthodontiaceae
is widespread in tropical and temperate regions, primarily epiphytic on
coniferous trees, decaying coniferous wood, or in terrestrial habitats. Buck
and Goffinet (2000) characterized the Orthodontiaceae as having no annulus;
Allen (2002) pointed out that the genus Orthodontium
in fact did possess an annulus. SELECTED
REFERENCES Allen, B. H. 2002. Moss
Flora of 1.
ORTHODONTIUM Schwägrichen, Sp. Musc. Frond., Suppl. 2 2((2)): 123. 1827 * [Greek,
orth-, erect, and odont-, tooth, and Greek diminutive -ium, alluding to straight or erect
peristome teeth] Plants densely foliose, shiny
or glossy, light yellow-green to
yellow-brown. Stems to 2 cm but
usually shorter, simple or forked at the base, moderately radiculose from
stem and leaf bases, radicles hyaline to reddish, smooth, with oblique
tangential walls, central cylinder relatively small. Leaves patent, dense at the base and crowded at stem apex, leaves
erect-spreading when dry, spreading when moist, keeled or shallowly carinate
with recurved or erect laminae, one or both laminae plane to
undulate-sinuolate, apex slenderly acute; margins plane or partly broadly recurved,
smooth, slightly denticulate in the apex; laminal cells apically short- to
long-rectangular median laminal cells long and narrow, linear to
linear-rhomboidal, firm-walled
distally, broader, thin-walled and laxly oblong-hexagonal proximally; 1--2 rows
of cells at insertion red-brown, equilateral to short-rectangular, somewhat
thicker than the larger and more lax cells just distal; costa usually ending
subapically, less often shortly excurrent, with or without stereid bands. Perichaetial leaves scarcely
differentiated. Seta slender,
erect-flexuose, yellowish. Capsule
symmetric, smooth when wet; exothecial cells pale brown to yellow-brown; stomata
phaneropore, located in the capsule neck; operculum obliquely rostrate; stomata phaneropore, located in the capsule
neck. Species
14 (2 in the flora): worldwide in tropical and temperate regions. Orthodontium was monographed by W.
Meijer (1951), and both species were treated in The
common Leptobryum pyriforme (Meessiaceae)
also has setaceous leaves, but the setaceous portion is distal to an abruptly
flaring base, the leaves are distant in the proximal part of the stem but
densely foliate distally, whereas in Orthodontium
the leaves are entirely setaceous and narrowed to the insertion, and dense
to the stem base. Leptobryum has a
horizontal or pendent pyriform capsule (not erect to suberect) which is
glossy (not dull or matte) brown. It also has a perfect peristome including
appendiculate cilia, but Orthodontium species have an endostome with a narrow basal
membrane with no cilia. Gametophytically
Orthodontium may resemble species of
Dicranaceae in the reddened and lax cells at the laminal insertion, but it
differs in the smooth, evenly long-rectangular to linear cells, subserrulate
apex, and narrow costa (see discussions of D. H. Norris and J. R. Shevock
2004a, 2004b). In
the western SELECTED
REFERENCES Andrews, A. Le Roy. 1932.
The 1.
Leaves narrowly setaceous, 0.1--0.2 mm wide at midleaf; distally flexuose wet
or dry; costa in cross section without stereid cells; paroicous or polygamous,
antheridia found among the perichaetial leaves or in buds below the
perichaetium; capsule subcylindric, exostome teeth smooth, basal membrane of
endostome none; endostome segments shorter than the teeth; operculum conic
and/or short- and obliquely rostrate .................1. Orthodontium gracile 1.
Leaves broadly linear, 0.5 mm wide at midleaf; 1\x twisted along the leaf length
wet or dry; costa in cross section with stereid cells; autoicous, antheridia found
only in buds below the perichaetium; capsule ovoid-pyriform (wider at or just
above the middle); exostome teeth finely papillose; basal membrane low; endostome
segments about as long as the teeth; operculum conic and long- and obliquely
rostrate ................. 2. Orthodontium
pellucens 1. Orthodontium gracile ( Bryum gracile Engl. Bot., 2835. 1838 Plants mostly 5--20(--30) mm,
glossy-vitreous. Stems without a
central strand. Leaves (1--)2--3(--4.5)
mm, 0.1--0.2 mm wide at midleaf, widest below the middle, narrowly setaceous,
margins broadly recurved; distally strongly flexuose wet or dry; costa in
cross section without stereid cells. Sexual
condition paroicous or polygamous, antheridia found among the
perichaetial leaves below the archegonia or in buds below the perichaetium. Seta 4--5(--9) mm. Capsule (1--)1.5--2 mm, subcylindric,
neck nearly as long as or to 1/3 the length of the capsule; exostome teeth
smooth, somewhat wider at the base, basal membrane of endostome none;
endostome segments shorter than the teeth; operculum conic and short- and
obliquely rostrate. Capsules
mature winter to early spring. Moist creek ravines and canyons, bases of
cliffs, riparian forests of Alnus,
Acer, Lithocarpus, Pseudotsuga, Sequoia, shaded decayed or charred logs
and stumps, bark base of trees, epiphytic on Sequoia sempervirens, peaty soil or soil over rock; moderate elevations; Calif., Oreg.; disjunct
to southwestern Mexico; West Indies; Central America; South America; w
Europe; Africa. 2. Orthodontium
pellucens
(Hooker) Bruch, Schimper & W. Gümbel, Syn. Musc. Frond. 1: 240. 1848 F Bryum pellucens Hooker, Icon. Pl. 1:
plate 34. 1836 Plants mostly 5--10 mm, shiny-opaque.
Stems with or without a central
strand. Leaves 2.5--5 mm, 0.5 mm
wide at midleaf, widest at the middle, broadly linear, keeled, margins erect; 1\x twisted
along the leaf length wet or dry; costa in cross section with stereid cells. Sexual condition autoicous,
antheridia found only in stalked buds which are numerous along the stem to
well below the perichaetium. Seta 7--14
mm. Capsule 1.5--1.7 mm, ovoid-pyriform
(wider at or just above the middle); with a rather short neck, exostome teeth
finely papillose, not much wider at the base; basal membrane present but low;
endostome segments about as long as the teeth; operculum conic and long- and obliquely
rostrate. Capsules
mature winter to early spring. In the East in peaty crevices of rock, treeless
heath balds of dense evergreen shrubs:
Rhododendron katawbensis, Kalmia latifolia, Gaylussacia baccata on
mountain summits, shaded rotten wood, bark of tree bases, pine logs and
stumps, peaty humus, soil, thin soil over calcareous rock, in the West in moist
creek ravines and canyons in moist forests of Pseudotsuga, Lithocarpus, Sequoia sempervirens, Vaccinium ovatum, Polystichum
muticum, Morella californica, Acer macrophyllum; low to high elevations
100--1500 m); Calif., Oreg., N.C., Tenn.; disjunct to south central and south
eastern Mexico; West Indies; Central America; South America; Pacific Islands
(Galapagos Islands, Hawaii). B.
H. Allen (2002) in his extensive treatment of these two species for Orthodontium pellucens
is a
species with perhaps the widest leaves in the genus in the median part of the
leaf, to 0.5 mm ( Orthodontium lineare Schwägrichen is a
species of Europe and the southern hemisphere in OTHER
REFERENCES Crum, H. A. & L. |
