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BFNA Title: Mesoptychia |
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XX. MESOPTYCHIA
(Lindberg) A. Evans, Ottawa Naturalist 17: 15 1903 [Greek mesos, middle, and ptychos, plica, alluding to weakly plicate leaves] Vadim Bakalin Jungermannia sect. Mesoptychia Lindberg, Kongl. Svenska.
Vetensk. Acad. Handl., n.s. 23 (5): 39. 1889; Leiocolea (Müller Friburg) H. Buch; Lophozia subgen. Leiocolea
Müller Friburg Plants 3--90 x 0.4--5
mm, prostrate to loosely ascending or rarely erect in dense patches, brown to
green-brown or yellowish brown. Stem
oval in section, 50--500 \um in width and 40--470 \um in height, outer cells
thick-walled, inner cells thinner-walled, or (in Leiocolea badensis) composed of uniform cells. Rhizoids brownish to colorless, at
right angles to stem, in tufts or tawny fascicles or scattered. Leaves contiguous to distant,
subimbricate in some Arctic phases, very obliquely to almost horizontally
inserted, dorsally not or short-decurrent, ventrally subtransversely
inserted, 2-lobed for 1/8--1/3 of leaf length to entire and emarginate, sinus
angular, crescentic or gibbous, lobes arcuate to biconcave, acute or rarely
rounded. Cells in midleaf mostly
elongate, walls thin, trigones large and convex to small, concave-sided, and
indistinct, cuticle coarsely papillose to almost smooth. Oil-bodies brownish, granulate, without central eye, 2--12 per
cell. Underleaves rarely obsolete, lanceolate and lacinulate,
undivided or 2- or 3-fid, frequently with acute teeth or (more rarely)
ciliate; rarely reduced to slime papillae. Specialized asexual reproduction not seen. Sexual condition
dioicous or monoicous. Androecia with
bracts not strongly inflated at base, with an additional tooth near dorsal
margin; antheridia 1--2(--3) per bract.
Perianth terminal on main stem, growth of stem rarely continuing by
adventitious branches proximal to perianth; bracts proximal to perianth in 1
pair; perianth tubular to tubular-subclavate, smooth or shallowly plicate,
mostly abruptly tightened to the beaked mouth, emergent from bracts for
1/2--3/4 of length, mouth crenulate to dentate, teeth 1--2(--3)-celled, of
elongate cells; perigynium absent or (rarely) present. Capsule wall (2--)3--4-stratose. Elaters 2-spiral. Species
16 (7 in the flora): North America, Eurasia. SELECTED
REFERENCES Hong W.S. 2002. Leiocolea
in Western North America. Lindbergia 27: 97--103. Schuster R.M. 1988. The
Hepaticae of South Greenland. Beih. Nova Hedwigia. Heft 92. 255 pp. 1. Plants 3--6 mm
wide; leaves widest in proximal third. 2. Plants
paroicous, secondary pigmentation brown, underleaves divided into 2--3 laciniae
bearing many cilia at narrow angle to lacinia margins, perigynium absent … 7.
Mesoptychia rutheana 2. Plants
dioicous, secondary pigmentation purple, underleaves mostly 2-lobed into two
lacunae, with margins bearing numerous cilia spreading at right angle with
margin, perigynium well developed, strongly rhizogenous, at right angle to
stem … 8. Mesoptychia sahlbergii 1. Plants 0.3-2.8
mm wide; underleaves laciniate, or 2-lobed to near base, cilia few or absent,
mostly with short teeth confined to underleaf base, or subentire; leaves
widest near middle, rarely in proximal third. 3. Leaves with
smooth or very obscurely papillose cuticle, plants not translucent, wider
than 1 mm, underleaves common, midleaf cells isodiametrical or nearly so,
commonly with strongly convex trigones, gemmae frequently present … 5. Mesoptychia heterocolpos 3. Leaves with
moderately to coarsely papillose, rarely obscurely papillose cuticle (rarely
almost smooth, but in the latter case plants translucent, narrower 1 mm wide,
underleaves obsolete or 1--5 cells long), midleaf cells mostly with concave
trigones, elongated; gemmae absent. 4. Plants
translucent, 0.3--0.6 mm wide, underleaves obsolete to small, up to 5 cells
long, mostly in the form of 1-seriate cilia, freely deciduous; perianth
beaked or not; capsule wall 2--3-stratose (where known) … 5 5. Plants paroicous, although archegonia never observed
fertilized, leaves mostly entire to emarginate, rarely bilobed … 6. Mesoptychia polymorpha 5. Plants dioicous, archegonia freely fertilized, leaves
clearly bilobed, with acite or nearly so lobes 1. Mesoptychia badensis 4. Plants not
translucent, 1--2.8 mm wide, underleaves regularly present, but frequently
hidden in tawny rhizoids, not deciduous, 2- to pluriseriate at the base;
perianth beaked; capsule wall 3--4-stratose. 6. Plants
monoicous, calciphilous or neutral habitats … 4. Mesoptychia gillmanii 6. Plants dioicous,
strictly calciphilous. 7. Midleaf cells
29--45 \um wide, leaves asymmetrical; plants 1.8--2.8 mm wide … 2. Mesoptychia bantriensis 7. Midleaf cells
22--35 \um wide; leaves almost symmetrical; plants 1.6--1.9 mm wide … 3. Mesoptychia collaris 1. Mesoptychia badensis (Gottsche) L. Söderström& Váňa,
Phytotaxa 65: 52. 2012 Jungermannia badensis Gottsche, Hepat. Eur., 95. 1859; Lophozia
badensis (Gottsche) Schiffner; L. badensis var. apiculata R.M. Schuster; Leiocolea badensis (Gottsche) Jørgensen Plants 3--8 x 0.3--0.6
mm, prostrate to ascending and semi-erect when growing between mosses,
brownish green with more deeply colored apical portion of perianth and female
bracts. Stem 100--180 \um in diameter, in section cells more or less
uniform, with thin or moderately thick walls, 15--22 \um in diameter,
external wall of stem thicker. Rhizoids colorless, in tufts or scattered. Leaves
contiguous to distant, almost symmetrical, rectangular, inserted at ca.
30--50° with axis, dorsally not decurrent, ventrally subtransversely
inserted, 270--450 x 250--420 \um, 0.9--1.1 times as long as wide, plane,
lobed 1/4--1/3 of length, sinus rectangular, lobes triangular, blunt. Cells
in midleaf 25--45 x 25--30 \um, walls thin, trigones medium in size,
triangular to convex; marginal cells 20--30 \um, thin-walled; cuticle distinctly papillose near ventral
leaf base, almost smooth in distal half of leaf. Oil-bodies
2--5(--7) per cell, spherical and 5--8 \um to (rarely) ellipsoidal, to 14
\um. Underleaves irregularly present and easily deciduous, mostly 2--3
cells in length, ca. 40--45 \um. Specialized asexual reproduction absent. Sexual
condition dioicous. Androecia intercalary on small
shoots, bracts in 3--4 pairs, concave
to cupped and channeled, commonly with one tooth near dorsal leaf base,
antheridia 1 per bract, bracteole absent or the same size as the stem
underleaves. Perianth tubular to tubular-clavate, smooth to loosely folded,
suddenly tightened to the beaked mouth,
emergent from bracts for 1/2--2/3 of its length, mouth crenulate to
dentate, frequently lacerate; trapezoidal, 2-lobed for 1/6--1/5 of the length, sinus
gibbous. Obligate calciphile,
growing on calcium-containing rocks and calcium rich sediments; low to high
elevations; Greenland; Alta., B.C., N.W.T., N.S., Nunavut, Que.; Alaska,
Ark., Colo., Iowa, Mass., Mich., Minn., Mont., N.H., N.Y., Tenn., Vt., Wis.;
Eurasia. The stem of Mesoptychia badensis is frequently
branching proximal to the perianth.The male plants are very small, ca.
0.3--0.35 mm wide. 2. Mesoptychia bantriensis (Hooker) L.
Söderström & Váňa, Phytotaxa 65: 52. 2012 Jungermannia bantriensis Hooker, Brit. Jungermann., 41. 1816; Lophozia
bantriensis (Hooker) Stephani; Leiocolea
bantriensis (Hooker) Jørgensen Plants 8--18 x 1.8--2.8
mm, prostrate to loosely ascending in dense patches, brown to green-brown or
yellowish brown. Stem 245--420 \um wide, 220--390 \um high; in section outer cells
strongly thick-walled, ca. 25 \um, inner cells thinner-walled, ca. 25--35
\um. Rhizoids brownish, in tufts. Leaves
contiguous, inserted at ca. 30--40° with axis, dorsally shortly decurrent,
ventrally subtransversely inserted, 845--1640 x 945--1645 \um, 0.9--1.15
times as long as wide, plane with lobes frequently incurved or flexed towards
the shoot apex, trapezoidal to orbicular or broadly oval, asymmetrical,
divided 1/7--1/5(--1/3) of leaf length, sinus angular or crescentic, lobes
arcuate to biconcave, acute. Cells in midleaf 37--50 x 29--45 \um,
elongate, walls thin, trigones large, bulging, marginal cells 30--48 \um,
thin-walled, but with thickened external wall; cuticle coarsely papillose throughout. Oil-bodies
2--8(--12) per cell, spherical and 4--9 \um to ellipsoidal and up 10--15 x 8
\um. Underleaves regularly present, lanceolate, ca. 300--650 \um,
frequently with acute teeth, teeth sometimes reduced to slime papillae. Specialized
asexual reproduction absent. Sexual condition dioicous. Androecia
bracts similar to sterile leaves, base not or obscurely inflated,
antheridia 2 per bract. Perianth
tubular to tubular-subclavate, smooth or shallowly plicate,
abruptly contracted to the beaked mouth,
emergent from bracts for 1/2--2/3 of the length, mouth dentate; bracts trapezoidal, 2-lobed 1/5--1/4 of the
length, sinus gibbous, lobes acute; stem
rarely branched proximal to perianth.
Moist, sandy,
calcium-rich or, at least, basic soil and rocks near streams, also wet basic
tundra; 0--3200 m; Greenland; Alta., B.C., Nfld. and Labr. (Nfld.), N.W.T., The stem of Mesoptychia bantriensis is rarely
branching proximal to perianth. 3. Mesoptychia collaris (Nees) L.
Söderström & Váňa, Phytotaxa 65: 53. 2012 Jungermannia collaris Nees, Fl. Crypt. Erlang., xv. 1817; Jungermannia
muelleri Nees ex Lindenberg; Leiocolea
alpestris (Schleicher) Isoviita; L.
muelleri (Nees ex Lindenberg) Jørgensen; Lophozia alpestris
(Schleicher) A. Evans; Leiocolea
collaris (Nees) Jøgensen Plants 5--10 x 1.6--1.9
mm, loosely ascending, brown to green brown.
Stem 250--350 \um wide,
200--250 \um high; in section outer cells ca. 17--22 \um in diameter, walls
thick, median lamina often darker; inner cells gradually larger, mostly
6--7-sided, ca. 20--28 \um in diameter, walls thin to slightly thickened. Rhizoids
brownish, numerous,in indistinct fascicles. Leaves contiguous,
inserted at 15--40º with axis, 850--875 x 825--935 \um, 0.95--1.1 as long as
wide, plane or slightly concave, oblique lingulate to oblique oval and
oblique trapezoidal, nearly symmetrical, 2-lobed for 1/5--1/4 of the leaf
length, sinus angular, U-shaped or gibbous, lobes arcuate to triangular,
blunt to rarely acute. Cells in midleaf 33--43 x 22--35 \um,
walls thin, brownish, trigones distinct, concave, marginal cells 28--38 \um,
walls thin, brownish, trigones triangular to slightly convex; midleaf cuticle obscurely to evidently
papillose. Oil-bodies 2--5(--9) per cell, spherical, 4--5 \um, to
ellipsoidal, to 14(--21) \um. Underleaves
regularly present to irregularly present, lanceolate, ca. 270--450 \um.
Specialized asexual reproduction
absent. Sexual condition dioicous.
Androecia intercalary,
resembling sterile shoot segments, bracts similar to sterile leaves but
frequently with one additional tooth near dorsal base, bracteole larger than
underleaves, lanceolate, entire;
antheridia 1 per bract. Perianth tubular to cylindrical-clavate, smooth,
abruptly contracted to the beaked mouth, emergent from bracts for 2/3--3/4 of
the length, mouth crenulate to shortly ciliate; bracts
trapezoidal, 2-lobed 1/5--1/4 of the length, sinus gibbous, lobes acute. Wet basic tundra,
over limestone on boulders along streams, also wet basic cliffs, mostly in non-forested
areas; low to high elevations (0--3000 m); Greenland; Alta., B.C., N.W.T.,
Sask., Yukon; Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Wash., Wyo.;
Eurasia. The male plants of Mesoptychia collaris are
smaller than the female. Prior to R. Grolle (1971), the name Lophozia alpestris was misapplied to L. sudetica; virtually all references
to L. alpestris in the North
American literature refer to L.
sudetica. 4. Mesoptychia gillmanii (Austin) L.
Söderström & Váňa, Phytotaxa 65: 53. 2012 Jungermannia gillmanii Austin, Bull. Torrey Bot. Club 2(3):
12. 1872; Leiocolea kaurinii (Limpricht)
Jørgensen; Lophozia gillmanii (Austin) R. M. Schuster; L. gillmanii var. ciliolata R. M. Schuster; Leiocolea
gillmanii (Austin) A. Evans Plants 7--20 x
1.75--2.45 mm, prostrate, brownish green to green-brown. Stem
175--280 \um wide, 160--270 \um high; in section cells ca. 25--38 \um,
surface crenulate, outer cell walls thickened (particularly the external
wall), inner cell walls thinner. Rhizoids
brownish, in dense tufts. Leaves
distant to contiguous, inserted at ca. 15--20° with axis, dorsally
decurrent in the biggest shoots, ventrally subtransversely inserted,
950--1000 x 1000--1050 \um, 1--1.1 as long as wide, plane to slightly convex,
obliquely trapezoidal, symmetrical to asymmetrical, 2-lobed for 1/9--1/5 of
leaf length, sinus angular or crescentic, lobes triangular to arcuate,
usually narrowed to an acute tip. Cells in midleaf 35--50 x 25--33 \um,
elongate, walls thin, colorless to grayish, trigones concave, marginal cells
20--28 \um, trigones moderate in size, concave to loosely convex; cuticle papillose throughout. Oil-bodies
2--8(--9) per cell, spherical, (3.5--)5--8(--10) \um in diameter to
ellipsoidal, to 12--13 \um. Underleaves
irregularly present, lanceolate, ca. 450--700
\um, commonly with a few teeth on each side. Specialized
asexual reproduction absent. Sexual condition paroicous. Androecia
in 2--3(--4) pairs of bracts, separated from perichaetium by 1 pair of
sterile leaves, bracts obliquely
trapezoidal, frequently with obtuse teeth on dorsal side. Perianth
tubular to ellipsoidal, smooth,
suddenly tightened to the beaked mouth,
emergent from bracts for 2/3 of the length, mouth dentate; bracts ovate to obliquely ovate, sometimes with teeth in middle of dorsal
side. Wet moist calcium
rich rocks, cliffs near waterfalls, calcareous solifluction spots near
snow-beds, basic swamps; low to high elevations (0--3000m); Greenland; Alta.,
B.C., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Ont., Que., Yukon; Alaska,
Ariz., Calif., Idaho, Maine, Mass., Minn., Mont., N.H., N.Y., Ohio, Oreg.,
Vt., Wash., Wis., Wyo.; Eurasia. The bracteoles of
Mesoptychia gillmanii are small,
2-fid, with lobes of different sizes. The spores are ca. 15 \um, finely
papillose, and the elaters are ca. 8 \um in width. 5. Mesoptychia heterocolpos (Thedenius) L.
Söderström & Váňa Phytotaxa 65: 53. 2012 Jungermannia heterocolpos Thedenius, Kongl. Vetensk. Acad. Handl. 1837: 52. 1838; Leiocolea holmeniana (Inoue &
Steere) Konstantinova; Lophozia
heterocolpos (Thedenius) M. Howe; Leiocolea
heterocolpos (Thedenius) H. Buch Plants 5--20 x 0.9--1.3 mm, prostrate
to ascending, with erect shoot apices bearing gemmae, green, apices deep green
to brownish deep green, older shoots brown. Stem ca. 250 \um wide,
190--240 \um high; in section outer cells with thick walls, ca. 12--17 \um in
diameter, inner cell walls thin to slightly thickened, ca. 22--28 \um in
diameter. Rhizoids brownish to almost colorless, sparse, in tufts. Leaves
distant to contiguous, inserted at ca. 35--45° with axis, 475--650 x 525--625
\um, 0.1--1.1 as long as wide, plane to slightly concave, ovate to
trapezoidal, nearly symmetrical, 2-lobed for 1/5-1/4 of the length, sinus
angular or U-shaped, lobes arcuate. Cells in midleaf 25--33 x
19--22(--30) \um, thin-walled, trigones large and bulging, marginal cells
14--22 /mu; cuticle mostly virtually
smooth, rarely papillose. Oil-bodies 2--8(--12) per cell,
spherical, 5--8(--11) \um, to ellipsoidal or tubular, 6--14(--16) x
4--7(--10) \um. Underleaves regularly present, 2-fid, divided almost to the base
(lobes connected by only 1--2 cells at base), ca. 200--350 \um. Specialized
asexual reproduction by gemmae present on leaf apices of modified erect
isophyllous shoots or unmodified branch apices, leaves bearing gemmae of
elongate cells with small trigones; gemmae brown, 25--30 x 15--20 \um,
2-celled, ellipsoidal. Sexual condition dioicous. Androecia
intercalary, semi-spicate, bracts in 3--4 pairs, concave, inflated at base,
sometimes with deflexed lobe apices, trapezoidal to ovate, with additional
teeth on dorsal side, antheridia 2 per bract.
Perianth clavate
to oblong ovate, suddenly or gradually narowed to the beacked mouth, emergent
from bracts for 2/3--3/4 of the length, mouth dentate; bracts trapezoidal, 2-lobed 1/5--1/3 of the
length, sinus gibbous, lobes acute. Varieties
3 (2 in the flora): North America, Eurasia. The elaters of Mesoptychia heterocolpos are 7--8 \um
in width, and the spores 11--13 \um, finely papillose. 1. Leaves plane
to weakly concave, inserted mostly at 35--40º with axis, gemmiparous shoots
common …5a. Mesoptychia heterocolpos var.
heterocolpos 1. Leaves
distinctly concave, inserted mostly at 40--50º with axis, gemmiparous shoots
rare … 5b. Mesoptychia heterocolpos var.
harpanthoides 5a. Mesoptychia heterocolpos var. heterocolpos Plants ascending to
semi-erect in dense moss patches. Leaves
plane to weakly concave, inserted mostly at 35--40º with axis. Cells in midleaf 18--28 \um wide. Gemmiparous shoots common. Wet or moderately
dry basic or neutral cliffs covered with humus, patches in oligotrophic bogs,
rarely on decaying wood; 0--3350m; Greenland; Alta., B.C., Nfld. and Labr.
(Nfld.), N.W.T., Nunavut, Ont., Sask., Yukon; Alaska, Calif., Colo., Idaho,
Maine, Mich., Minn., Mont., Nev., N.H., N.C., Oreg., Utah, Vt., Wash., Wis.,
Wyo.; Eurasia. A specimen from
Ohio, as noted by Schuster (1969), requires verification. 5b. Mesoptychia heterocolpos var. harpanthoides (Bryhn
& Kaalaas) L. Söderström & Váňa, Phytotaxa
65: 53. 2012 Lophozia harpanthoides Bryhn & Kaalaas, Rep. Second
Norweg. Arctic Exped. Fram 1898---1902, 11: 31 1906; Lophozia heterocolpos
var. harpanthoides (Bryhn & Kaalaas) R. M. Schuster; Leiocolea harpanthoides (Bryhn &
Kaalaas) A. Evans; L. heterocolpos var. harpanthoides (Bryhn & Kaalaas) S. W. Arnell Plants commonly erect,
growing in dense moss patches. Leaves
clearly concave, inserted mostly at 40--50º to stem. Cells in midleaf 18--28 \um wide. Gemmiparous shoots rare. Calcareous to
neutral mossy tundras, as a rule among mosses in dense patches, and near
snow-beds; low to moderate elevations; Greenland; Nunavut, Que.; n 6. Mesoptychia polymorpha Stotler, Crandall-Stotler & Bakalin,
Polish Botanical Journal 58: 82. 2013 Plants 3--6 x 0.6--1.5
mm, prostrate to ascending, pale yellow green without secondary pigments. Stem
140–180 \um wide and 100–125 \um high, in section cells more or less
uniform, with thin walls and lacking trigones, 25--35 \um in diameter,
external wall of stem slightly thicker.
Rhizoids sparse to
abundant, grayish brown. Leaves contiguous to distant, highly
variable in shape, from broadly obovate to obtrapezoidal, rectangular or
lingulate, with the apices varying from obtuse to truncate, or retuse,
emarginate, with the lobes mostly obtuse and unequal in size, inserted at ca.
15--40° with axis, dorsally not decurrent, ventrally subtransversely
inserted, 250--700 x 250--600 \um, 0.9--1.1 times as long as wide, plane. Cells
in midleaf 30--65 x 27--46 \um, walls thin, trigones absent to vestigial,
marginal cells 27--45 \um, thin-walled; cuticle finely striolate. Oil-bodies
(2--)3--5(--8) per cell, elliptical to spheroidal, gray, coarsely granulate,
3.8–5.7 µm in diameter and up to 9.5 µm long.
Underleaves irregularly
present and easily deciduous, mostly 2--6(--8) cells long, ca. 40--280 \um. Specialized
asexual reproduction absent. Sexual condition paroicous. Androecia
intercalary, bracts in 2--4 pairs,
concave to cupped and channeled, commonly with one tooth near dorsal
leaf base, antheridia 1(--2) per bract, bracteole absent or highly reduced. Perianth
clavate to obpyriform, smooth, suddenly tightened to the beaked
mouth, emergent from bracts for
1/2--2/3 of its length, mouth crenulate to dentate; bracts trapezoidal, 2-lobed for 1/6--1/5 of the length, sinus
gibbous, bracteole absent or up to 120 \um long. Continuously
moist, deeply shaded calcareous substrates; 45--210 m; Calif. The stem of Mesoptychia polymorpha is rarely
branched, with branches only of the lateral, endogenous Plagiochila-type. 7. Mesoptychia rutheana (Limpricht) L. Söderström & Váňa Phytotaxa
65: 54. 2012 Jungermannia rutheana Limpricht, Jahresber. Schles. Ges. Vaterl.
Cult. 61: 207 1884: Lophozia rutheana (Limpricht) M. Howe; Leiocolea rutheana (Limpricht) Müller Plants 30--150 x
4.2--4.9 mm, prostrate, brown to greenish brown. Stem
ca. 400 \um wide, 290 \um high, in section outer cells 15-30 \um in diameter
with thick walls, inner cell walls thin to slightly thickened. Rhizoids
dense to sparse or virtually absent, short, brownish to almost colorless,
isolated or in tufts. Leaves contiguous, inserted at ca.
10--15° with stem, dorsally barely decurrent, 1625--2520 x 1925--3100 \um,
0.7--0.85 as long as wide, slightly convex to almost plane, obliquely
trapezoidal, asymmetrical, widest at middle or just proximal, 2-lobed for ca.
1/5 of length, sinus gibbous to crescentic, frequently valvate in margin near
sinus base, lobes angular, arcuate to biconcave, with blunt to acute apices. Cells
in midleaf 43--60 x 30--38 \um, thin-walled, walls brown, trigones large
and bulging, marginal cells 22-30 \um in diameter, with thin to slightly
thickened walls and convex trigones; cuticle
coarsely papillose. Oil-bodies 2--6 per cell, mostly
ellipsoidal, 7--20 x 5--9 \um. Underleaves regularly present,
1--3--lobed, middle lobe commonly larger, ca. 1400--1750 \um (lateral laminae
ca. 1000 \um), commonly with 2--10 laciniae and cilia spreading at narrow
angles. Specialized asexual reproduction absent. Sexual
condition paroicous. Androecia proximal to perichaetium,
in 1--2 pairs of bracts, similar to sterile leaves but loosely inflated in
basal part, antheridial stalk 2--seriate.
Perianth fusiform, loosely folded, gradually
narrowed to the mouth, emergent from bracts for 3/4--4/5 of length, mouth not
beaked; bracts just proximal to perianth, in 1 pair,
smaller than sterile leaves, 2-lobed for 1/5 of length, sinus narrowly
gibbous or angular, acute lobes. Rich fens and
springy swamps, exclusively on basic substrates; 0--1300 m; Greenland; Alta.,
B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., Que., The elaters of Mesoptychia rutheana are 8--10 \um
wide and the spores are (12--)16--20 \um, pale brown. 8. Mesoptychia sahlbergii (Lindberg & Arnell) A. Evans,
Ottawa Naturalist 17: 15. 1903 Jungermannia sahlbergii Linsberg & Arnell, Kongl. Svenska
Vetensk. Acad. Handl., n.s. 23(5): 40. 1889; Lophozia sahlbergii (Lindberg & Arnell) Stephani Plants 30--60(--90) x 3--5
mm, prostrate, brownish red to red-purple, rarely brown. Stem
300--500 \um wide, 250-400 \um high, in section outer cells 15-30 \um with
thick walls, inner cell walls thin to slightly thickened. Rhizoids
dense, short to long, brownish to almost colorless, forming mat under stem. Leaves
contiguous to subimbricate, inserted at ca. 10--15° with stem, dorsally
barely decurrent, 1400--3000 x 1500--3500 \um, 0.7--0.9 as long as wide,
slightly convex to almost plane, loosely plicate along midline, obliquely
trapezoidal, asymmetrical, widest near base, 2-lobed for 1/10--1/5 of length,
sinus gibbous to crescentic, frequently valvate in margin near sinus base,
lobes angular, mostly arcuate, with blunt to acute apices. Cells
in midleaf 30--50 x 32--40 \um, thin-walled, walls brown, trigones large
and bulging, marginal cells 22--30 \um in diameter, with thin to slightly
thickened walls and convex trigones; cuticle coarsely papillose. Oil-bodies
3--8 per cell, mostly ellipsoidal, rarer nearly spheric, 6--12 x 4--6 \um. Underleaves
regularly present, 1--2--lobed, 1000--1800 \um, with numerous cilia spreading
at right angles. Specialized asexual reproduction absent. Sexual
condition dioicous. Androecia, in 2--4 pairs of bracts,
similar to sterile leaves but loosely inflated in basal part and with
additional small lobe at dorsal side, antheridial stalk 2-seriate. Perianth fusiform, loosely folded, gradually
narrowed to the mouth, emergent from bracts for 3/4--4/5 of length, mouth not
beaked; perigynium well developed, ca. the same length as perianth, at right
angle with stem, strongly rhizogenous, bracts just proximal to perianth, in 1
pair, larger than sterile leaves, 2-lobed for 1/5 of length, sinus narrowly
gibbous or angular, lobes acute. Rich fens and
springy swamps, exclusively on basic substrates; 0--500 m; Greenland; Nunavut;
Yukon; Alaska; Eurasia. The elaters of Mesoptychia sahlbergii are 7--9 \um
wide and the spores are 12--15 \um, brown. |
