BFNA Title: Eurhynchiastrum
XX. Eurhynchiastrum Ignatov & Huttunen, Arctoa 11: 260. 2002  * [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.
Sp. Musc. Frond., 265, plate 68: figs. 1--4. 1801; Eurhynchium
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).
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
var. diversifolium (Schimper) Ochyra & Żarnowiec; E. pulchellum var. praecox (Hedwig) Ochyra & Żarnowiec; Eurhynchium
(Renauld & Cardot)
Grout, E. substrigosum
Kindberg; E. pulchellum
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.
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
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.
Crum, H. A., W. C. Steere, and L. E. Anderson 1965 . A list of the mosses of
De Notaris, G. 1867. Cronaca della briologia italiana. Comment. Soc. Crittog. Ital. 2: 269--312.