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BFNA Title: Eurhynchiastrum |
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XX. Eurhynchiastrum Ignatov & Huttunen, Arctoa 11: 260. 2002 [2003] * [Eurhynchium,
and Latin -astrum, incomplete resemblance] Michael S.
Ignatov Plants small to medium-sized, in loose to
dense tufts, green or yellowish to brownish, glossy. Stems prostrate
to arching, with central strand, loosely to densely terete-foliate, rather
irregularly densely branched, branches obtuse by smaller, more crowded and
more obtuse leaves at their tips; axillary hairs 3--4-celled; juvenile branch
leaves acute. Stem leaves loosely to closely imbricate or somewhat
spaced, erect to erecto-patent, broadly
ovate-triangular to ovate-lanceolate, broadest at 1/10 of leaf length or
below, gradually tapered to apex or broadly acuminate, sometimes blunt at
apex, rounded to base, narrowly decurrent, slightly concave, smooth or in
large plants plicate, margins plane or recurved near base, serrulate to
subentire; costa strong, reaching 0.6--0.85 the leaf length, ending in a
spine; juxtacostal basal cells slightly shorter, but not clearly differentiated
from cells above, cells above decurrency broader,
isodiametric, relatively thin-walled, forming a small, more or less distinct subquadrate group and often surrounded by small subquadrate cells forming a more or less extensive, but
indistinctly delimited group; mid laminal cells linear, smooth. Branch
leaves smaller and narrower than stem leaves, blunt, smooth or, in large
plants, plicate, costa to 0.6--0.9 the leaf length, cells just before apex
short, nearly isodiametric or irregular in shape. Sexual condition
phyllodioicous or dioicous; perichaetial leaves reflexed, gradually acuminate
from a sheathing base, entire or occasionally serrulate, costa weak and
short, reaching to about half of basal part of leaf. Seta red-brown, smooth
or rarely very slightly rough at places. Capsule red-brown, inclined
to horizontal, oblong, slightly curved dorsally, annulus separating by
fragments; operculum rostrate; peristome perfect. Calyptra naked. Spores 12--17 /um, slightly papillose. Species 1 (1
in the flora): North America, Central America, Eurasia, Africa, Eurhynchiastrum
was segregated from
the polyphyletic Eurhynchium
(M. S. Ignatov and S. Huttunen 2002), where it was placed by most authors.
Other authors, e.g. G. De Notaris (1867), H. Robinson
(1987), and K. D. McFarland (2004), accepted its placement in Rhynchostegium.
North American species of Rhynchostegium differ from Eurhynchiastrum in their robust
habit and lack of an abaxial spine at end of costa. In the present concept, Eurhynchium is
strictly a Palearctic genus. SELECTED REFERENCE Grout, A.
J. 1898. A revision of the North American Eurhynchia.
Bull. Torrey Bot. Club 25: 221--256. 1. Eurhynchiastrum pulchellum (Hedwig)
Ignatov & Huttunen, Arctoa 11: 262. 2002 [2003] Hypnum
pulchellum Hedwig,
Sp. Musc. Frond., 265, plate 68: figs. 1--4. 1801; Eurhynchium
pulchellum (Hedwig) Stems 2--5(--13) cm, branches to 3--8(--17)
mm. Stem leaves 0.5--1.3(--2.6) x 0.2--0.9(--1.8) mm; basal cells near
costa 7--10 /um wide; cells just proximal to decurrency
12--20 x 10--15 /um; mid-leaf cells 30--75(--100) x 4.5--6 /um. Branch leaves 0.4--1.3(--1.6) x
0.2--0.5(--1.1) mm. Seta 1--1.8
cm. Capsule 1.5 mm. Varieties 2 (2
in the flora). Eurhynchiastrum
pulchellum is easy to recognize by the characteristically blunt
branch leaves. The most common phenotype for plants on soil and tree trunk
bases in forests is light green plants with rigid erect leaves. In xeric and
Arctic environments leaves (of both stems and branches) become strongly
appressed, with shoots julaceous, and these plants are often brownish and
quite fragile. They have been segregated as var. praecox (temperate areas, branch leaves 0.5--0.8 mm, alar cells
as in typical variety) and var. diversifolium (Arctic-alpine,
branch leaves 0.5--0.6 mm, alar cells very numerous) but these grade to
typical phenotypes and thus do not merit taxonomic recognition despite a
sometimes distinctive appearance. The seta is almost always smooth in this
species, but some few collections, described as Eurhynchium strigosum var. scabrisetum Grout, from New
Jersey, New York and Massachusetts have roughened setae, although the
mammillae are very low, appearing as a shallowly wavy outline, mostly at mid
seta. In various parts of 1. Stem leaves
0.5--1.3 mm long; branch leaves 0.2--1.1 x 0.2--0.5(--0.6) mm, not or
slightly plicate . . . 1a. Eurhynchiastrum pulchellum var. pulchellum 1. Stem leaves
1.2--2.6; branch leaves 1--1.9 x 0.4--0.8(--1) mm, strongly plicate . . . 1b.
Eurhynchiastrum pulchellum var.
barnesii 1a. Eurhynchiastrum pulchellum
(Hedwig) Ignatov &
Huttunen var. pulchellum Eurhynchiastrum pulchellum
var. diversifolium (Schimper) Ochyra & Żarnowiec; E. pulchellum var. praecox (Hedwig) Ochyra & Żarnowiec; Eurhynchium
fallax
(Renauld & Cardot)
Grout, E. substrigosum
Kindberg; E. pulchellum
var. robustum
(Roll) Stems 2--10 cm. Stem leaves 0.5--1.3 x 0.4--0.9 mm. Branch leaves 0.2--1.1 x
0.2--0.5(--0.6) mm, not or slightly plicate. Soil in
forests, rocks, decaying logs and stumps, tree bases, in a broad range of
environmental conditions from shady rock vertical surfaces and wet slopes of
forested ravines to open ground in xeric steppe areas, and among other mosses
in tundra, granite, limestone; 0--3200 m; Greenland; Alta., B.C., Man., N.B.,
Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md.,
Mass., Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Mex., N.Y.,
N.C., N.Dak., Ohio, Okla., Oreg., Pa., S.C., S.Dak., Tenn., Tex., Utah, Vt.,
Va., Wash., W.Va., Wis., Wyo. Mexico; Central America; Eurasia; n and e
Africa. Sporophytes of
E. pulchellum
var. pulchellum are rare, confined probably to forest
environments. There are no collections from a few states and provinces, but
the var. pulchellum
apparently occurs throughout the flora area with probably the only exception
being 1b. Eurhynchiastrum pulchellum
var. barnesii (Renauld & Cardot) Ignatov, xxxxxxx. 2008 Eurhynchium strigosum var. barnesii
Renauld & Cardot, Revue Bryologique
15: 72. 1888; E. pulchellum var. barnesii (Renauld & Cardot) H. A.
Crum, W. C. Steere
& L. E. Anderson; E. taylorae R. S. Williams Stems 6--13 cm. Stem leaves 1.2--2.6 x 0.6--1.8 mm. Branch leaves 1--1.9 x 0.4--0.8(--1)
mm, often broadly obtuse, strongly plicate. Soil, rocks,
and decaying logs; probably middle elevations; ca. 500 m; Alta., B.C.; Alaska, Calif., Colo., Idaho,
Mont., Wash. Eurhynchiastrum pulchellum var. barnesii seems to be a
relatively rare and endemic plant, probably deserving the status of species.
Its separation from the large expressions of var. pulchellum needs additional
attention. OTHER
REFERENCES: Crum, H. A., W. C. Steere, and L. E. Anderson 1965 [1966]. A list of the mosses of De Notaris, G. 1867. Cronaca della briologia italiana. Comment.
Soc. Crittog. Ital. 2: 269--312.
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