BFNA Title: Bryhnia
Author: M. Ignatov 
Date: September 26, 2009
New Aug. 3, 2010
Edit Level: R2 
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Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

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XX. Bryhnia Kaurin, Bot. Not. 1892: 61. 1892  *  [For Nils Bryhn, 1854--1916, Norwegian bryologist]

Michael S. Ignatov


Plants small to robust, green, or yellowish to brownish green. Stems prostrate to ascending or arching, with central strand, unevenly foliate, alternating cochleariform parts with moderately loose foliage or moderately dense with very loose, irregularly to regularly pinnately branching; branches straight, moderately densely terete- to complanate-foliate; axillary hairs 3--4-celled. Stem leaves imbricate-appressed, erect, patent, or rigidly spreading, ovate or ovate- triangular and broadly acute to ovate-lanceolate and then tapered to a long acumen, decurrent; margins serrate distally, serrulate proximally; costa ending in distal portion of leaf, smooth or ending in an abaxial spine; basal cells indistinctly differentiated, thick-walled; alar cells (or sometimes only sub-alar cells) isodiametric, rather large and thin-walled, indistinct or distinct; laminal cells elongate-flexuose, moderately to strongly thick-walled, distal cell ends prorate to papillose on abaxial surface. Branch leaves narrower and smaller than stem leaves, acute to acuminate (more acute than stem leaves), with margins and abaxial surface of costa more strongly serrate and abaxial lamina more toothed. Sexual condition dioicous; perichaetial leaves with reflexed acumens. Seta brownish orange to red brown, rough. Capsule brownish orange to red brown, inclined to horizontal; annulus separating by fragments; operculum high-conic, tapered to a broad beak; peristome xerocastique, perfect. Spores 13--18 \um. Calyptra naked.


Species ca. 5--10 (3 in the flora): North America, South America, Eurasia.


The circumscription of Bryhnia needs a re-evaluation with DNA markers since morphology seems to be misleading. In Japan and adjacent areas, N. Takaki (1956) accepted 15 species within Bryhnia, but only six survived a revision by A. Noguchi (1991). Most were synonymized with B. novae-angliae. Among North American species, B. graminicolor is not closely related to the “core” group of the genus and possibly has to be segregated in its own genus.


1. Plants small, stems to 2 cm; stem leaves narrowly ovate to lanceolate, 0.6--1.1 x 0.25--0.5 mm . . . 1. Bryhnia graminicolor

1. Plants medium-sized to robust, stems usually much longer than 2 cm; stem leaves broadly ovate-triangular to ovate, 0.7--1.5 x 0.7--1.2 mm.

2. Stem leaves ovate-triangular to ovate, 1--1.6 mm, usually longer than broad, acute, rarely cucullate, more or less imbricate but not julaceous (except rarely along some portions of the stem); alar cells usually gradually differentiated; eastern North America . . . 2. Bryhnia novae-angliae

2. Stem leaves broadly ovate-triangular, 0.7--1.2 mm, often shorter than broad, rounded or broadly acute, often truncate and short-apiculate, often cucullate, julaceous; alar cells abruptly differentiated; Alaska and British Columbia . . . 3. Bryhnia hultenii


1. Bryhnia graminicolor (Bridel) Grout, Bull. Torrey Bot. Cl. 25: 231. 1898


Hypnum graminicolor Bridel, Musc. Recent. Suppl. 2: 251. 1812


Plants small, in moderately dense, soft tufts, light green or brownish yellow-green. Stems to 2 cm, prostrate to ascending, straight or flexuose, terete foliate, rather regularly pinnately branched; branches to 5 mm, straight, terete-foliate. Stem leaves rigidly spreading, narrowly ovate to lanceolate, broadest at 1/5--1/6\x leaf length, not or slightly plicate, 0.6--1.1 x 0.25--0.5 mm, rounded to base, short-decurrent; margins plane or partially recurved, usually only below the broadest point of the leaf, serrulate to serrate almost to base; gradually acuminate; costa moderately weak, reaching 0.6--0.8\x leaf length, ending in an abaxial spine; basal cells shorter in ca. 2 rows, little differentiated from cells above, 7--8 \um wide, thick-walled; alar cells subquadrate to short rectangular, 10--20 x 7--9 \um, forming a small group of about 4 x 4 cells, moderately thick-walled, indistinctly differentiated, sometimes obscured by a recurved portion of the leaf margin; laminal cells elongate, 25--45 x 5--6 \um, strongly papillose at distal corners, the rough surface of leaves readily observed under stereo-microscope and 10\x hand lens. Branch leaves smaller and narrower, more strongly serrulate. Seta 7--15 mm. Capsule inclined, cylindric, not or slightly curved, about 1.6 mm, operculum high-conic and broadly rostrate. Spores 13--15 \um.


Rock faces, crevices, and ledges, soil, often steep banks along roads and creeks, rarely wood, moist shaded to rather open habitats; 0--900(--2040) m; Nfld. and Labr., Ont., Que.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Vt., Utah, Va., W.Va., Wis.


Bryhnia graminicolor usually occurs at low elevations, reaching to 900 m in the Appalachian Mountains. One collection from Utah: Utah Co., Mt. Timparrogos, 2040 m, wet logs and lumber, Flowers 17045 (MO!) is the most western collection of this species, and the habitat is unusual. This discovery was not included by S. Flowers (1971) and mislabeling of the specimen is suspected in this case. Confirmation of its occurrence in the western states is necessary.


2. Bryhnia novae-angliae (Sullivant & Lesquereaux) Grout, Bull. Torrey Bot. Cl. 25: 229. 1898


Hypnum novae-angliae Sullivant & Lesquereaux, Musci Hepaticae U.S., reprint 338 [Schedae 73]. 1856


Plants medium-sized, in moderately loose to dense tufts, light to dark green, or yellowish to brownish green. Stems to 10 cm, prostrate to arching, slightly curved or flexuose, terete to sub-complanate foliate, with rather numerous sub-dendroid sympodial branches and with occasional rather regular pinnate branching; branches to 7 mm, straight to slightly curved, sub-complanate to complanate-foliate. Stem leaves closely to loosely imbricate, rarely julaceous along some portions of the stem, erect, or patent and then twisted to contorted, ovate-triangular to ovate, broadest at 1/7\x leaf length or more proximally, not or weakly plicate, 1--1.5 x 0.7--1.1 mm, longer than broad, rounded to base, decurrent; margins plane or recurved proximally, serrulate or serrate almost to base; apex acute or gradually to abruptly short-acuminate, rarely cucullate; costa strong, reaching 0.6--0.8\x leaf length, ending in an abaxial spine; basal cells somewhat shorter than cells above, 10--13 \um wide, thick-walled; alar cells short-rectangular, enlarged, to 30 x 12--16 \um, moderately thick-walled, forming a rather conspicuous, although relatively small pellucid group not reaching the leaf margin, gradually differentiated; laminal cells elongate, rhombic-elongate distally, often distinctly flexuose, 20--40 x 4---6 \um, variable among different leaves on the same plant, ranging from 3--8:1, usually strongly prorate to prorate-papillose on abaxial surface. Branch leaves smaller and rather uniform in size, ovate-lanceolate, often with short, twisted acumens, more strongly serrate, costa with stronger spine and cells more strongly prorate-papillose. Seta 10--20 mm. Capsule inclined to horizontal, slightly curved, 1.5--2 mm; operculum high-conic to shortly and broadly rostrate. Spores 14--18 \um.


Soil, sometimes rocks, rotten logs, wet shady places, forest, along small brooks, wet places on slopes; 0--1900 m; N.B., Nfld. and Labr. (Nfld., Labr.), N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., Del., Ga., Ill., Ind., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.; Europe; e Asia.


Bryhnia novae-angliae is a common plant in eastern North America, reaching south into Georgia and Alabama. Records from Alaska appear to be B. hultenii. Both species are highly variable, so morphotypes at the margins of their ranges may have almost identical characters. The common phenotype of the species has its branch leaves rigidly spreading and markedly smaller than stem leaves, but this is not consistent, and sometimes plants are quite similar to Brachythecium rivulare. However, the shorter, usually strongly prorate to prorate-papillose laminal cells indicate Bryhnia. Bryhnia novae-angliae is especially variable near its southern limit. Some plants in that region are little branched. Other specimens, particularly from North Carolina, have blunt leaves resembling Eurhynchiastrum pulchellum; such plants differ in having flexuose and shorter laminal cells and larger plant size.


3. Bryhnia hultenii E. B. Bartram in A. J. Grout, Moss Fl. No. Amer. 3: 264. 1934


Plants medium-sized, in moderately loose to dense tufts, light green or yellowish to brownish green. Stems 2.5--7 cm, prostrate to dendroid-arching, terete-foliate, with rather numerous sub-dendroid sympodial branches, occasionally with rather regular pinnate branching; branches to 6 mm, straight to slightly curved, terete- to complanate-foliate. Stem leaves julaceous, broadly ovate-triangular, broadest at ca. 1/7 of leaf length or below, strongly concave, slightly plicate, 0.7--1.2 x 0.8--1.2 mm, often shorter than 1 mm and shorter than broad; apices broadly acute to rounded-truncate and short-apiculate, often cucullate, rounded to base, broadly and long-decurrent; margins plane or partially recurved, serrulate to near base; costa weak, reaching 0.4--0.7\x the leaf length, lacking an abaxial spine; basal cells shorter and wider  in 2--3 rows, indistinctly delimited from cells above, to 15 \um wide, thick-walled; alar cells subquadrate to short-rectangular, usually enlarged, up to 45 x 25 \um, forming a pellucid group of 5--7 x 8--14 cells, moderately thin-walled, reaching 1/2--4/5\x distance to the costa, distinctly delimited; laminal cells elongate to rhombic, strongly flexuose, 15--40 x 6--12 \um, thick-walled, slightly prorate to prorate-papillose on abaxial surface. Branch leaves smaller, rounded-ovate, about 0.6 x 0.5 mm, with smaller cells and almost undifferentiated basal cells. Sexual condition dioicous. [Capsule inclined to horizontal, slightly curved, ca. 1.5 mm; operculum conic.]


Soil and rocks at cliff bases, under dense Alnus canopy, bottom of gullies, sides of brooks, moderate to strong shade, wet to mesic places; 0--300 m; B.C.; Alaska; ne Asia.


The description of the capsules of Bryhnia hultenii is from Asian collections, as no sporophytes have been found in North America to date. Records of this species from eastern North America are referred to B. novae-angliae. The two species are closely related, but, although some specimens are difficult to interpret, most specimens can be distinguished. The appearance of B. hultenii is rather different from B. novae-angliae, as its stem foliage is julaceous, and its leaves are rather equal in size, strongly concave, and cucullate. Microscopic characters are highly variable. Bryhnia  hultenii can usually be distinguished from B. novae-angliae by its sharply differentiated alar region, composed of thin-walled, pellucid cells, as well as by the costa becoming thin distally and lacking a spine. H. Robinson (1962) thought that B. hultenii was not distinct from B. novae-angliae.




Noguchi, A. 1991. Illustrated moss flora of Japan. Hattori Botanical Laboratory, Nichinan.


Robinson, H. 1962 [1963]. Generic revisions of North American Brachytheciaceae. Bryologist 65: 73--146.


Takaki, N. 1956. Researches on the Brachytheciaceae of Japan and its adjacent areas III. J. Hattori Bot. Lab. 16: 1--71.