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BFNA Title: Straminergon |
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CALLIERGONACEAE-- Straminergon vers. 1 XXX. STRAMINERGON Hedenäs, J. Bryol. 17:
462. 1993 * Lars Hedenäs Plants medium-sized, pale or whitish green to
yellow-green. Stem sparsely and
irregularly branched, with central strand and without hyalodermis,
inner cortical cells thin-walled; outer pseudoparaphyllia
broad, triangular to irregular in outline; rhizoids or rhizoid initials at
various points on the leaves, or on scattered points or in rows on the stem;
axillary hairs with 1--2 distal hyaline cells. Stem leaves straight, ovate or narrowly ovate, distally suddenly
narrowed to a rounded and often cucullate apex, not plicate, concave; margin
entire; costa single, ending 60--90% way up leaf; median lamina cells
incrassate or thin-walled, eporose to porose; alar cells quadrate or
shortly to longly rectangular, hyaline or when old
brownish, thin-walled or somewhat incrassate, inflated, in ovate or broadly
ovate group, distinctly delimited from surrounding cells, decurrent,
but often narrowly so. Sexual
condition dioicous. Inner
perichaetial leaves not plicate; vaginula
naked. Capsule curved and ±
horizontal; annulus not separating; exostome reticulate on basal outer side,
margin distally dentate. Spores
12.5--23 \um. Species 1 (1
in the flora): widespread. The genus Straminergon
was earlier included in Calliergon. The single member of Straminergon differs from those
of the latter genus in its mostly pale green to pale straw-colored shoots and
in having markedly smaller and sparsely branched shoots. Further, it has much
smaller and sparse axillary hairs and its alar
groups are ovate to broadly ovate along the basal leaf margin. SELECTED
REFERENCES Hedenäs, L. 1993. A generic revision of the Warnstorfia-Calliergon group. J. Bryol. 17: 447--479. Hedenäs,
L. 2006. Additional
insights into the phylogeny of Calliergon, Loeskypnum, Straminergon,
and Warnstorfia (Bryophyta:
Calliergonaceae). J. Hattori Bot. Lab. 100: 125--134. Janssens,
J. A. 1983. Wynne, F. E. 1945. Studies in Calliergon and related genera. Bryologist 48: 131--155. 1. Straminergon
stramineum (Dickson
ex Bridel) Hedenäs, J. Bryol. 17: 463. 1993 Hypnum stramineum Dickson ex
Bridel, Muscol. Recent. 2(2): 172. 1801; Calliergon stramineum (Dickson ex Bridel) Kindberg Plants whitish to yellowish green. Stem sparsely branched. Stem leaves straight, ovate or
narrowly ovate, distally suddenly narrowed to a rounded and often cucullate
apex; median lamina cells 40.0-88.0 \um long; alar
groups ovate or broadly ovate. Widespread in mineral-poor to mineral-rich, but not
calcareous, and nutrient-poor to -rich fens, shores, or irrigated rocks; low
to high elevations; Greenland; Alta., B.C., Man., N.B., Nfld.
and Labr., N.B., N.J., N. Mex., N.S., N.W.T., Nunavut, Ont.,
P.E.I., Que., Sask., Yukon; Alaska, Calif., Colo., Conn., Idaho, Mass., Mich.,
Minn., Mont., N.H., N.Y., Ohio, Oreg., Pa., Va., Vt., Wis., Wash., Wyo., Utah;
South America; n Eurasia; Africa; Pacific Islands (New Zealand); Australia. Straminergon
stramineum
is usually easy to recognise due to its pale and
sparsely branched shoots and its oblong, ovate, or narrowly ovate leaves with
rounded apices. This is one of the Calliergonaceae in
which the rhizoid initial cells close to the leaf apex frequently produce
rhizoids, which can then be seen as small brownish tufts from some leaves.
Occasionally, S. stramineum
is confused with the autoicous Calliergon cordifolium in the field. However, small modifications
of the latter with comparatively narrow leaves have indistinctly delimited,
large alar groups which reach from the leaf margin
to the costa or almost so, whereas the alar groups
of S. stramineum
are well delimited and ovate or broadly ovate along the basal margin. For
the differences between S. stramineum and Sarmentypnum sarmentosum,
see the note after the latter. |
