Oligotrichum falcatum

Steere

Bryologist 61: 115, figs. 1–9. 1958,.

Treatment appears in FNA Volume 27. Treatment on page 145. Mentioned on page 143, 144.

Plants green to silvery green, reddish-brown with age. Stems 1.5–2 (–5) cm, simple to much branched by innovations. Leaves 1.5–3 mm, asymmetrically ovate to ovatelanceolate, arcuate-incurved and falcate-secund when wet or dry; costa percurrent, the apex cucullate with a sharp point, smooth abaxially or slightly roughened; lamina strongly inflexed distally, smooth abaxially or with low teeth or abaxial lamellae only near apex; margins of lamina distantly serrulate or almost entire; adaxial lamellae 8–16, undulate, 4–10 (–13) cells high, in profile irregularly serrulate and notched, the marginal cells in section undifferentiated, smooth; median basal-cells short-rectangular, sometimes with small groups of alar cells larger; median cells of lamina isodiametric to short-rectangular, 6–15 (–18) µm wide, walls firm, thickened at the angles; marginal cells ± at right angles to the margin, marginal teeth minute, unicellular; leaves of male plants only weakly falcate; perichaetial leaves longer and straighter than the vegetative leaves, convolute-tubulose, almost straight. Seta 1–1.5 cm. Capsule 3.5–4 mm, cylindric, widest at the base and tapering towards the mouth, sometimes indistinctly angled; operculum conic with a short beak; peristome teeth 32, tapering, subacute, often compound. Spores 19–21 µm.


Habitat: Wet soil and rocks, slopes and bare, non-calcareous gravelly soil, lake shores, dripping rocks by waterfalls, often beside or submerged in snow-melt streams
Elevation: moderate to high elevations (200-1800 m)

Distribution

V27 179-distribution-map.gif

Greenland, Nfld. and Labr. (Labr.), Nunavut, Yukon, Alaska, Asia (Russia in Siberia)

Discussion

Oligotrichum falcatum is widely distributed in the Arctic. It is locally common and not infrequently fruiting in northern Alaska and Yukon. In Nunavut, it is known from Axel Heiberg and Melville islands. Similar to O. hercynicum, it is distinguished by the regularly falcate-secund leaves, with abaxial lamellae scarcely developed. Steere noted that in the field, submerged plants have a silvery-green appearance, due to air trapped in the abaxial cells of the costa.

Lower Taxa

None.

"widest" is not a number."longer and narrower" is not a number.

... more about "Oligotrichum falcatum"
prominent +
Gary L. Smith Merrill +
Steere +
abrupt +, crisped +  and undulate +
firm-textured +
broadened +
overlapping +
monoicous +, dioicous +, sexual +  and vegetative +
sparsely ciliate;smooth +
cucullate +
sometimes +  and rugose +
angled +, tapering +  and cylindric +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
toothed +
undifferentiated +
not differentiated +
Greenland +, Nfld. and Labr. (Labr.) +, Nunavut +, Yukon +, Alaska +  and Asia (Russia in Siberia) +
moderate to high elevations (200-1800 m) +
pitted +  and not papillate +
scabrous +, mammillose +  and smooth +
larger +  and small +
Wet soil and rocks, slopes and bare, non-calcareous gravelly soil, lake shores, dripping rocks by waterfalls, often beside or submerged in snow-melt streams +
delimited +  and indistinct +
not differentiated +
photosynthetic +
serrate +, crenulate +  and serrulate +
with low teeth or abaxial lamellae +  and smooth +
isodiametric +  and short-rectangular +
6um +  and 15um +
entire +  and serrulate +
falcate-secund +
asymmetrically ovate +  and ovatelanceolate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
membranous +
entire;sharply serrate +
cuticular-papillose +  and smooth +
denticulate +  and subentire +
shape +  and size +
dioicous +  and sexual +
short-rectangular +
straight +  and longer and straighter +
convolute-tubulose +
pigmented +  and pale +
subacute +  and tapering +
steere1976a +
underground +
undifferentiated +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
differentiated +
larger +  and minute +
branched +  and simple to much +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Oligotrichum falcatum +
Oligotrichum +
species +
compound +  and simple +
unjointed +
reddish-brown +, green +  and silvery green +
small +  and medium-sized +