Plagiomnium medium

(Bruch & Schimper) T. J. Koponen

Ann. Bot. Fenn. 5: 146. 1968.

Basionym: Mnium medium Bruch & Schimper Bryol. Europ. 4: 196, plate 398. 1838
Synonyms: Plagiomnium medium subsp. curvatulum (Lindberg) T. J. Koponen P. medium var. curvatulum (Lindberg) H. A. Crum & L. E. Anderson
Treatment appears in FNA Volume 28. Treatment on page 234. Mentioned on page 230, 231.

Erect stems 2–4 cm, not dendroid; sterile stems to 8 cm. Leaves green or yellow-green, crisped and contorted when dry, flat when moist, elliptic, broadly elliptic, or sometimes obovate or oblong, (3.5–) 4–7 (–10) mm; base long-decurrent; margins toothed to near base, teeth sharp or occasionally blunt, of 1–2 (–3) cells; apex obtuse, rounded, acute, acuminate, or rarely retuse, mucronate or cuspidate, cusp sometimes toothed; costa percurrent or excurrent; medial laminal cells usually elongate, short-elongate, or occasionally ± isodiametric, (35–) 50–65 (–85) µm, less than 1/2 size near margins, in longitudinal or diagonal rows, collenchymatous, walls pitted; marginal cells linear, in 2–4 rows. Sexual condition synoicous. Seta (1–) 3 (–7), yellow to reddish or orange with age, 2–5 cm. Capsule pendent, oblong, cylindric, or narrow-ovoid, 3–4.5 mm, neck not distinct; operculum conic-apiculate. Spores 20–36 µm.


Phenology: Capsules mature late spring.
Habitat: Soil, humus, rock, tree bases in wet forests, cliffs/talus, fire-dependent forests, swamps
Elevation: low to moderate elevations

Distribution

V28 373-distribution-map.gif

Greenland, Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Alaska, Ark., Calif., Colo., Idaho, Ill., Iowa, Maine, Mich., Minn., Mont., Nev., N.Y., Oreg., Pa., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., Wis., Wyo., Europe, Asia, Africa

Discussion

Plagiomnium medium has most often been confused with 2. P. ciliare and 7. P. insigne; see the discussions of those species. The considerable morphological variation within P. medium may also reflect confusion with at least one undescribed species. One British Columbian collection that closely resembles P. medium is dioicous and has larger leaves and laminal cells. The leaf marginal teeth in P. medium are often hooked forward when composed of multiple cells.

Selected References

None.

Lower Taxa

None.
... more about "Plagiomnium medium"
blackish +, orange-yellow +, reddish-brown +, yellowish-brown +, yellowish green +, red +, brown +  and yellow +
cuspidate +  and apiculate +
Cuspidate (?) +, Mucronate (?) +, Retuse (?) +, Acuminate (?) +, Acute (?) +, Rounded (?) +  and Obtuse (?) +
Terry T. McIntosh +  and Steven G. Newmaster +
(Bruch & Schimper) T. J. Koponen +
long-decurrent +
Mnium medium +
cucullate +
yellowish-brown +  and yellow +
narrow-ovoid +, cylindric +  and oblong +
0.3 cm3 mm <br />0.003 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
undifferentiated +
1 (?) +  and 2 (?) +
nodulose +
excurrent +  and percurrent +
subpercurrent +
toothed +
Greenland +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. +, N.W.T. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Alaska +, Ark. +, Calif. +, Colo. +, Idaho +, Ill. +, Iowa +, Maine +, Mich. +, Minn. +, Mont. +, Nev. +, N.Y. +, Oreg. +, Pa. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Vt. +, Va. +, Wash. +, Wis. +, Wyo. +, Europe +, Asia +  and Africa +
low to moderate elevations +
yellow +  and yellowish-brown +
brown +  and yellow +
lanceolate-acuminate +
Soil, humus, rock, tree bases in wet forests, cliffs/talus, fire-dependent forests, swamps +
crowded +  and distant +
elliptic +  and contorted +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
yellow-green +  and green +
oblong +, obovate +  and crisped +
larger +  and small +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
yellow-green +  and green +
synoicous +  and sexual +
rhomboidal +  and linear +
isodiametric +, short-elongate +  and elongate +
not distinct +
rostrate +  and conic-apiculate +
Capsules mature late spring. +
Ann. Bot. Fenn. +
smaller +  and larger +
yellow +  and reddish or orange +
straight +  and flexuose +
elongate +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
spheric +
not dendroid +
brownish +, yellow-green +  and green +
0 cm0 mm <br />0 m <br /> (8 cm80 mm <br />0.08 m <br />) +
Plagiomnium medium subsp. curvatulum +  and P. medium var. curvatulum +
Plagiomnium medium +
Plagiomnium +
species +
blunt +  and sharp +