Schistidium frigidum

H. H. Blom

Bryophyt. Biblioth. 49: 181, fig. 70. 1996,.

Treatment appears in FNA Volume 27. Treatment on page 217. Mentioned on page 209, 210, 214, 216, 218.

Plants in open, occasionally flattish tufts or cushions, olivaceous, often in part yellow-green, rarely blackish. Stems 1–2 (–4) cm, central strand distinct or absent. Leaves erect or slightly curved, usually imbricate when dry, narrowly ovatelanceolate to ovatelanceolate, sharply keeled distally, 1.1–2.1 mm, 1-stratose, rarely with 2-stratose striae distally; margins recurved to just before the apex, often denticulate distally, 1-stratose or 2-stratose; apices acute or somewhat obtuse; costa excurrent as a coarsely denticulate, often slightly flexuose, usually decurrent awn, rarely percurrent (in alpine habitats), smooth; some basal-cells sometimes much lighter than adjacent cells, often hyaline, sometimes with yellowish walls, marginal cells quadrate or elongate-rectangular, often strongly trigonous or with more thickened transverse walls; distal cells often of various shapes, short-rectangular or isodiametric, sometimes ovate or subtriangular, 6–10 µm wide, usually strongly sinuose. Sexual condition autoicous. Capsule redbrown, sometimes orangebrown, cylindric, 0.7–1.1 mm; exothecial cells irregularly shaped, isodiametric or oblate, thin-walled or slightly thickened, trigonous; stomata present; peristome patent to squarrose, sometimes revolute, 230–300 µm, orange-red or yellowish red, densely to finely papillose, weakly perforated. Spores 10–14 µm, granulose or nearly smooth.


Phenology: Capsules mature late spring to early summer.
Habitat: Rock in open to shaded habitats
Elevation: moderate to high elevations (500-3300 m)

Distribution

V27 294-distribution-map.gif

Greenland, Alta., B.C., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Ont., Que., Yukon, Alaska, Colo., Idaho, Mich., Mont., Nev., N.Mex., Oreg., Wash., Wyo., Eurasia

Discussion

Schistidium frigidum is rather common yet is one of the more difficult taxa to determine with confidence, as the examination of many leaves is often necessary before the elongate basal marginal cells are obvious. Often, some central basal cells are much lighter than adjacent cells, and are often hyaline, and form contrasting patches, which helps to identify the species. In contrast to S. dupretii and S. confertum, which have a large proportion of elongate exothecial cells, S. frigidum has exothecial cells that are mainly isodiametric or oblate.

Selected References

None.

Lower Taxa

None.

"um" is not declared as a valid unit of measurement for this property.

... more about "Schistidium frigidum"
deciduous +  and persistent +
obtuse +  and acute +
multistratose +
Terry T. McIntosh +
H. H. Blom +
flexuose +
not papillose +
decurrent +  and denticulate +
hyaline +  and sometimes much lighter +
sinuous +  and straight to sometimes +
rectangular +
divided +
undifferentiated +
plicate +  and smooth +
not papillose +
mitrate +  and cucullate +
small;large +
sulcate +  and smooth +
orangebrown +  and redbrown +
long-exserted +
striate +  and smooth +
cylindric +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
thin +  and thick +
percurrent;excurrent +
subpercurrent +
reniform +, elliptical +  and terete +
usually not markedly larger +
autoicous +  and sexual +
subtriangular +, ovate +, isodiametric +  and short-rectangular +
2-stratose +  and 1-stratose +
Greenland +, Alta. +, B.C. +, Nfld. and Labr. (Nfld.) +, N.W.T. +, Nunavut +, Ont. +, Que. +, Yukon +, Alaska +, Colo. +, Idaho +, Mich. +, Mont. +, Nev. +, N.Mex. +, Oreg. +, Wash. +, Wyo. +  and Eurasia +
moderate to high elevations (500-3300 m) +
trigonous +, oblate +, isodiametric +  and irregularly--shaped +
reproduction +  and asexual +
dioicous +, autoicous +  and sexual +
Rock in open to shaded habitats +
papillose +, mammillose +  and smooth +
specialized +
dioicous +, autoicous +  and sexual +
keeled +, narrowly ovatelanceolate +  and ovatelanceolate +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
2-stratose;1-stratose +
denticulate +
with more thickened transverse walls +, trigonous +, elongate-rectangular +  and quadrate +
thick-walled +  and sinuose +
papillose +  and smooth +
subtriangular +, ovate +, rectangular +  and quadrate +
thick-walled +  and sinuose +
papillose +  and smooth +
yellow-green +
not +  and differentiated +
yellowish red +  and orange-red +
patent +  and squarrose +
lanceolate;linear +
Capsules mature late spring to early summer. +
Bryophyt. Biblioth. +
straight +
sigmoid +  and arcuate +
papillose +  and smooth +
short to long +
ornamented +  and smooth +
smooth +  and granulose +
globose +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
muticous;long-awned +
Schistidium frigidum +
Schistidium +
species +
flattish +
4 cm40 mm <br />0.04 m <br /> (18 cm180 mm <br />0.18 m <br />) +
blackish;olivaceous +