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BFNA Title: Meesiaceae |
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MEESIACEAE Dale H. Vitt Plants acrocarpous, erect to ascending,
simple to sparsely branched. Leaves ovate-lanceolate to ligulate;
costa strong, single. Seta slender and usually very long,
to 10 cm. Capsule clavate; with an erect, long, well-defined neck abruptly
merging to a wider, smooth, horizontal, spore-bearing portion. Peristome
diplolepidous, exostome of 16, short, obtuse teeth (but elongate in Paludella), endostome of 16 longer
segments, cilia short or absent. Calyptra cucullate. Genera 4 (3 in
the flora): widespread in northern North America, Europe, and Asia, disjunct
in South America, Africa, The family is
characterized by capsules with long necks that abruptly expand into the spore
sac. These acrocarpic plants have no
differentiated alar cells, generally occur on peaty substrates, have long
setae, and reduced diplolepideous peristomes. SELECTED
REFERENCES Crum, H. and L. E. Anderson. Meesiaceae. Mosses of 1.
Leaves squarrose-recurved (moist or dry); leaf cells bulging-conic . .
. 3. Paludella 1.
Leaves erect, flexuose to wide-spreading); leaf cells smooth. 2.
Leaf cells lax, thin-walled; oblong-rhombic to oblong-hexagonal . . .
1. Amblyodon 2.
Leaf cells firm-walled; irregularly isodiametric to shortly rhombic .
. . 2. Meesia 1. AMBLYODON Palisot de Beauvois. Magasin Encyclopédique 5: 323. 1804, name
conserved * [Greek ambly, blunt, obtuse, and odon, tooth, alluding to the blunt
peristome teeth] Leaves loosely erect to erect-spreading, not
3-ranked; margins plane; cells distally lax, pellucid, thin-walled,
oblong-rhombic to oblong-hexagonal, smooth, basal cells similar to the
distal. Species 1:
North America, Europe, Amblyodon is characteristically found in
calcareous fens and meadows. 1. Amblyodon dealbatus (Hedwig) Bruch & Schimper in P.
Bruch, W. P. Schimper and W. Gümbel, Bryol. Eur. 4: 7. (fasc. 10. Monogr. 5) 1841 Meesia dealbata Hedwig., Spec. Musc. Frond., 174. 1801 Plants to 1(--2.5) cm. Stem leaves loosely erect to flexuose when dry,
erect-spreading when moist; narrowly
oblong, 2--4 mm, not decurrent, sharply acuminate-acute; margins plane,
entire or subentire; costa wide, ending well before apex. Sexual
condition usually autoicous. Seta
1.2--4 cm. Capsule 2--3
mm. Spores 30--40 µm. Sporadically
on rotting wood and organic soil in rich fens scattered across the boreal
zone; Alta., B.C., Man., Nfld., N.W.T., Nunavut, Ont., Que., Yukon;
Alaska, Colo., Mich., Minn., Mont., Wis., Wyo.; North America; Europe; Asia.
The lax,
thin-walled leaf cells distinguish Amblyodon
dealbatus from species of Meesia. 2. MEESIA
Hedwig, Spec. Musc. Frond., 173.
1801, conserved name * [For David Meese, 1723--1770, Dutch gardener] Leaves erect to wide-spreading, some species
3-ranked; margins plane to reflexed below to recurved throughout; cells
distally firm-walled, irregularly isodiametric to short-rhombic, smooth,
longer basally. Species 12 (3
in the flora): North, Central, and South America; Europe; Asia; Africa; Meesia occurs
on calcareous soil banks and in rich fens in boreal, alpine, and Arctic
situations. 1. Leaves ligulate, not 3-ranked, erect when
moist, leaf margins revolute basally . . . 1. Meesia uliginosa 1. Leaves ovate-lanceolate to lanceolate,
3-ranked, spreading when moist, leaf margins plane basally . . . . 2.
Leaves serrulate distally; dioicous . . . 2. Messia triquetra 2.
Leaves entire; synoicous . . . 3. Meesia
longiseta 1. Meesia longiseta Hedwig, Spec. Musc. Frond. 173. 1801 Plants 0.4--0.8 cm. Stem leaves spreading
and somewhat twisted when dry, irregularly spreading and indistinctly
3-ranked when moist; ovate-lanceolate
to lanceolate, 2--3.5 mm, decurrent, acute to narrowly obtuse; margins reflexed
in basal portion of leaf, entire; costa narrow, ending in or just before
apex. Sexual condition
synoicous. Seta 5--11 cm. Capsule 3.5--4.5
mm. Spores 36--44 µm. Calcareous soil
banks and rich fens in boreal, alpine, and Arctic situations; Alta., B.C.,
Man., Nunavut, N.W.T., Ont., Yukon; Alaska, Calif., Conn., Idaho, Ind., N.H.,
N.Y.; boreal and Arctic Eurasia. Meesia longiseta is distinguished from M. triquetra by the entire leaf
margins, synoicous sexual condition, and leaves generally more slender. This species occurs in habitats similar to
those of M. triquetra. 2. Meesia triquetra (Jolyclerc) Ångström, Nova Acta Reginae
Soc. Sci. Upsal. 12: 357. 1844 Mnium triquetrum Jolyclerc, Systême Sexuel des Végétaux,
749. 1803 Plants 0.1--1.2 cm. Stem leaves contorted
when dry, wide-spreading and distinctly 3-ranked when moist; ovate-lanceolate, 1.5--4 mm,
decurrent, acute; margins reflexed below, serrulate; costa narrow, ending in
or just below apex. Sexual condition dioicous. Seta 3--10 cm. Capsule 3--4.5 mm. Spores 33--38 µm. Rich fens in
arctic and boreal areas and disjunct in a few locations farther south; Greenland; Alta., B.C., Man., Nfld. and
Labr (Nfld.), N.W.T., Nunavut, Ont.,
Que., Yukon; Alaska, Calif., Mich., Minn., Mont., Nebr., N.J., N.Y., Oreg.,
S.Dak., Vt.; boreal and Arctic Eurasia. Meesia triquetra is a species frequent where appropriate
habitat is available. It is usually
easily distinguished by three-ranked, widely spreading leaves that have
serrulate margins. The sexual
condition is dioicous. Meesia uliginosa has ligulate leaves
with clearly revolute margins. The
quadrate distal leaf cells differentiate species of Meesia from Amblyodon
dealbatus, which has elongate, pellucid leaf cells. 3. Meesia uliginosa Hedwig, Spec. Musc. Frond., 173. 1801 Plants 0.1--0.3 cm. Stem leaves erect to flexuose when dry,
erect when moist; ligulate to
narrowly lanceolate, 2--4 mm, not decurrent, obtuse to rounded; margins
revolute to near apex, entire; costa wide, ending just before apex. Sexual
condition usually dioicous. Seta
1.5--5 cm; capsule 1.5--4 mm. Spores 40--51 µm. Rich fens,
moist calcareous soil banks, and soil covered rock crevices; Greenland; Alta.,
B.C., The ligulate
leaves and strongly revolute leaf margins are distinguishing features of Meesia uliginosa. The leaves are erect when moist or dry and
the costa is quite strong. The seta
are generally much shorter than those of either M. triquetra or M.
longiseta. 3. PALUDELLA Bridel, Muscol. Recent. Suppl. 3:
72. 1817 * [Greek palus, marsh,
alluding to marshy habitat] Leaves squarrose-recurved, not 3 ranked;
margins broadly reflexed near middle; distal leaf cells thick-walled,
rounded-hexagonal, bulging-conic on both surfaces, longer basally. Species 1; circumboreal, North America; Paludella is a monotypic genus occurring in
calcareous fens. 1. Paludella squarrosa (Hedwig) Bridel, Muscol. Recent. Suppl.
3: 72. 1817 Bryum squarrosum Hedwig, Sp. Musc. Frond., 186. 1801. Plants about 3--7 cm. Stem leaves squarrose-recurved,
stiff when moist or dry, obovate to elliptic, 1.5--2 mm, acute to shortly
acuminate; margins broadly reflexed, serrulate distally; costa narrow, ending below apex. Sexual
condition dioicous. Seta 2.5--4.5 cm. Capsule 2--3 mm. Spores
15--22 µm. Calcareous wet
fens; Greenland; Alta., B.C., Paludella squarrosa is one of the most spectacular moss
species in the flora. The
squarrose-recurved leaves (more squarrose than in any other species, even Rhytidiadelphus squarrosus) combined
with the calcareous wet fen habitat are all that is needed for
identification. |
