Rhizomnium gracile

T. J. Koponen

Ann. Bot. Fenn. 10: 16, figs. 62–73. 1973.

Synonyms: Mnium gracile (T. J. Koponen) H. A. Crum & L. E. Anderson M. koponenii H. A. Crum
Treatment appears in FNA Volume 28. Treatment on page 239. Mentioned on page 237, 238.

Plants 1–3 (–5) cm. Stems dark red or reddish-brown, or brown when old; micronemata present, often indistinct. Leaves green or occasionally pale reddish or reddish-brown, variously contorted when dry, obovate or orbicular, 1.5–3 (–4) mm; margins green or rarely reddish or pale-brown, blackish on older leaves, 1-stratose; apex rounded or rarely retuse, rarely short-apiculate; costa ending well before apex to 7/8 leaf length or rarely longer, often 2-fid distally; medial laminal cells elongate, 35–65 (–100) µm, collenchymatous, walls pitted; marginal cells linear, rhomboidal, or ± rectangular, in 1–2 (–3) rows. Sexual condition dioicous. Seta 1.5–2 cm. Capsule ovate to subglobose, 1–1.5 mm; operculum conic; exostome brown, lamellae less than 20. Spores 28–36 µm.


Phenology: Capsules mature summer.
Habitat: Muskegs, bogs, seeps, cliff crevices, moist soil, peat, humus
Elevation: low elevations

Distribution

V28 383-distribution-map.gif

Alta., B.C., Man., Nfld. and Labr., N.W.T., Ont., Que., Sask., Yukon, Alaska, Europe

Discussion

The leaves of Rhizomnium gracile are usually unpigmented, including the margins. Rhizomnium pseudopunctatum is similar in appearance but distinguished by its synoicous sexual condition, larger leaves, and usually pigmented leaf border.

Selected References

None.

Lower Taxa

None.
... more about "Rhizomnium gracile"
blackish +, orange-yellow +, reddish-brown +, yellowish-brown +, yellowish green +, red +, brown +  and yellow +
Retuse (?) +  and Rounded (?) +
Terry T. McIntosh +  and Steven G. Newmaster +
T. J. Koponen +
long-decurrent +
Mnium sect. Rhizomnium +
cucullate +
yellowish-brown +  and yellow +
horizontal;pendent +
ovate +  and subglobose +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
undifferentiated +
2 (?) +  and 1 (?) +
nodulose +
percurrent +  and excurrent +
subpercurrent +
0 +  and 7/8 +
toothed +
Alta. +, B.C. +, Man. +, Nfld. and Labr. +, N.W.T. +, Ont. +, Que. +, Sask. +, Yukon +, Alaska +  and Europe +
low elevations +
yellowish-brown +  and yellow +
lanceolate-acuminate +
Muskegs, bogs, seeps, cliff crevices, moist soil, peat, humus +
0 +  and 20 +
crowded +  and distant +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
reddish-brown +, pale reddish +  and green +
2-fid +, orbicular +  and obovate +
larger +  and small +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
blackish +, pale-brown +, reddish +  and green +
dioicous +  and sexual +
rectangular +, rhomboidal +  and linear +
Capsules mature summer. +
Ann. Bot. Fenn. +
smaller +  and larger +
pale +, orange +  and reddish-brown +
flexuose +  and straight to somewhat +
elongate +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
spheric +
not dendroid +  and simple +
brown +, reddish-brown +  and dark red +
arching +  and erect +
indistinct +
sinuate +
Mnium gracile +  and M. koponenii +
Rhizomnium gracile +
Rhizomnium +
species +
blunt +  and sharp +