Ptychostomum bimum

(Schreber) J. R. Spence

Phytologia 87: 20. 2005.

Basionym: Mnium bimum Schreber Bot. Zeitung (Regensburg) 1: 79. 1802
Synonyms: Bryum bimum (Schreber) Turner
Treatment appears in FNA Volume 28. Treatment on page 158. Mentioned on page 157, 162, 164.

Plants in dense turfs, green or yellow-green. Stems 1.5–3 (–4) cm, comose, innovations elongate and evenly foliate; often strongly radiculose. Leaves green, weakly twisted to contorted when dry, ovate, flat to weakly concave, (1–) 2–3 (–3.5) mm, not much enlarged toward stem apex; base weakly decurrent; margins revolute to mid leaf or beyond, limbidium strong, in 2 or 3 rows; apex acute; costa short-excurrent, awn smooth; proximal laminal cells 3–4: 1, same width or narrower than more distal cells; medial and distal cells rhomboidal, 12–18 µm wide, 3–4: 1, walls firm to sometimes very incrassate, sometimes at oblique 30–45° angle to costa. Specialized asexual reproduction absent. Sexual condition synoicous. Seta 1–3 (–4) cm. Capsule brown, elongate-ovate, symmetric, 3–5 mm, mouth yellow; operculum conic, apiculate; peristome well developed; exostome teeth yellow basally, hyaline distally, lamellae usually straight mid-tooth, pores absent along mid line; endostome not adherent to exostome, basal membrane high, 1/2 exostome height, segments with ovate perforations, cilia long, appendiculate. Spores (10–) 12–16 µm, finely papillose, pale-yellow or green.


Phenology: Capsules mature May–Aug.
Habitat: Wet soil, soil over rock, rock
Elevation: low to high elevations (0-3000 m)

Distribution

V28 250-distribution-map.gif

Greenland, Alta., B.C., Man., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Kans., Maine, Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.J., N.Dak., Ohio, Oreg., Pa., Utah, Vt., Wash., W.Va., Wis., Wyo., South America, Eurasia, Africa, Pacific Islands (New Zealand), Australia

Discussion

Ptychostomum bimum has in the past been considered a form of P. pseudotriquetrum, but V. I. Zolotov (2000) provided characters that can generally separate the two species. Ptychostomum bimum is a common species on damp to wet soil or soil over rock, but its distribution is not well understood as it has had little recognition in the past. The species appears to be much more common than P. pseudotriquetrum in eastern North America.

Selected References

None.

Lower Taxa

None.

"narrower" is not a number."narrow" is not a number.

... more about "Ptychostomum bimum"
specialized +
synoicous +, sexual +  and asexual +
John R. Spence +
(Schreber) J. R. Spence +
denticulate +
reduced +
curved +  and straight +
decurrent +
Mnium bimum +
cucullate +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
nutant +, inclined +  and suberect +
long-exserted +
elongate-ovate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
inflated +
not differentiated +
appendiculate +
short-excurrent +
subpercurrent +
rhomboidal;hexagonal +
Greenland +, Alta. +, B.C. +, Man. +, Nfld. and Labr. +, N.W.T. +, N.S. +, Nunavut +, Ont. +, Que. +, Sask. +, Yukon +, Alaska +, Ariz. +, Calif. +, Colo. +, Conn. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Maine +, Mass. +, Mich. +, Minn. +, Mo. +, Mont. +, Nebr. +, Nev. +, N.H. +, N.J. +, N.Dak. +, Ohio +, Oreg. +, Pa. +, Utah +, Vt. +, Wash. +, W.Va. +, Wis. +, Wyo. +, South America +, Eurasia +, Africa +, Pacific Islands (New Zealand) +  and Australia +
low to high elevations (0-3000 m) +
hyaline;pale-yellow +
not adherent +
hyaline +, brown +, orange +  and yellow +
hyaline +  and yellow +
Wet soil, soil over rock, rock +
not +  and differentiated +
narrowly ovatelanceolate;triangular +
polyoicous +, monoicous +, dioicous +  and sexual +
imbricate;variously contorted +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
erect;erect-spreading +
flat +  and weakly concave +
enlarged +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
2-stratose +  and 1-stratose +
revolute entire +  and denticulate +
1 (?) +, 3 (?) +  and 4 (?) +
short-rectangular +  and quadrate +
lateral +  and terminal +
lateral +  and terminal +
diplolepidous-alternate +
Capsules mature May–Aug. +
differentiated +
smooth;papillose +
not absent +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
straight +  and flexuose +
elongate +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
green +  and pale-yellow +
germinating +
variable +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
Bryum bimum +
Ptychostomum bimum +
Ptychostomum subg. Cladodium +
species +
lanceolate +
distinct +
not +  and porose +
straight +
specialized +
polyoicous +, autoicous +, synoicous +, dioicous +  and sexual +
sinuate +
incrassate +
yellow-green +  and green +
large;small to very +