BFNA Title: Bryhnia
Author: M. Ignatov
Date: September 26, 2009
Edit Level: R
Version: 1

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden
BFNA Web site: http://www.mobot.org/plantscience/BFNA/bfnamenu.htm

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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 rather robust, green, yellowish, to brownish green. Stems prostrate, with central strand, unevenly foliate, alternating cochleariform parts with moderately loose foliage or moderately dense with very loose, irregularly to regularly pinnately branched, branches straight, moderately densely and sub-complanate foliate; axillary hairs 3--4-celled; juvenile branch leaves acute. Stem leaves imbricate-appressed, erect to patent, sub-orbicular or broadly triangular and broadly acute to ovate-lanceolate and then tapered to a long acumen, decurrent; margin serrate distally, serrulate proximally; costa ending in distal portion of leaf, often with a spine abaxially; laminal cells elongate-flexuose, moderately thick-walled, sometimes forming tooth-like projections on abaxial surface; alar cells (or sometimes only sub-alar cells) isodiametric, rather large and thin-walled, forming indistinctly delimited group. Branch leaves narrower and smaller than stem leaves, acute to acuminate (sharper than stem leaves), with margin 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 the genus Bryhnia needs a complete re-evaluation with DNA markers. Morphology seems to be especially misleading. In Japan and its adjacent areas, N. Takaki (1956) first split the genus into 15 species, but only six survived the revision by A. Noguchi (1991). M Most were synonymized with B. novae-angliae. Three of the remaining species show transitions to B. novae-angliae in the broad sense, but two are distinct. Their position in this genus is, however, not obvious. Among North American species, B. graminicolor is not 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 to rounded-ovate, 1--1.4 x 0.7--1.1 mm.

2. Stem leaves ovate-triangular, 1.1--1.5 mm, longer than broad, acute, rarely cucullate, more or less imbricate but not julaceous (except rarely along some portions of the stem); stems more or less closely branched, forming moderately dense to, less commonly, loose tufts; alar cells gradually differentiated from supra-alar cells; branch leaves ovate-lanceolate, often with a short, twisted acumen; eastern North America . . . 2. Bryhnia novae-angliae

2. Stem leaves broadly ovate-triangular, 0.7--1.2 mm, often shorter than 1 mm and shorter than broad, rounded to shortly apiculate, often cucullate, julaceous; stem sparsely branched, forming loose tufts; alar cells abruptly differentiated from supra-alar cells; branch leaves rounded-ovate, and twisted acumen absent except in tiny plants; Alaska . . . 3. Bryhnia hultenii

1. Bryhnia graminicolor (Bridel) Grout, Bulletin of the Torrey Botanical Club 25: 231. 1898

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

Plants small, in moderately dense, soft tufts, light green or brownish yellow, not glossy. Stems to 2 cm, prostrate to ascending, straight or flexuose, terete foliate, rather regularly pinnately branching; branches to 5 mm, straight, terete foliate. Stem leaves usually well spaced, rigidly spreading, 0.6--1.1 x 0.25--0.5 mm, narrowly ovate to lanceolate, broadest at 1/5--1/6 of leaf length, gradually acuminate, rounded to base, short-decurrent, not or slightly plicate, margins plane or partially recurved, almost always below broadest point of leaf, serrulate to serrate almost to base; costa moderately weak, reaching 0.6--0.8 of leaf length, ending in a spine abaxially; basal cells near costa shorter in ca. 2 rows, little differentiated from laminal cells distally, 7--8 \um wide, thick-walled, in leaf corner subquadrate to short rectangular, 10--20 x 7--9 \um, moderately thick-walled, forming a small group of about 4 x 4 cells, sometimes obscured by a recurved portion of the leaf margin; laminal cells elongate, 25--45 x 5--6 \um, strongly papillose at distal cell corner, the rough surface of leaves easily 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 grows at low elevations, reaching to 900 m in the Appalachian Mountains. There is one collection from high mountains in Utah: Utah Co., Mt. Timparrogos, 2040 m, wet logs and lumber, S. Flowers 17045 (MO!). Also, this is the most western collection of this species, and the habitat is unusual. For some reason this discovery was not included by S. Flowers (1971). Mislabeling of the specimen is suspected. In any case, confirmation of this species’ 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 rather regular pinnate branching in some places; branches to 7 mm, straight to slightly curved, sub-complanate to clearly complanate-foliate. Stem leaves closely to loosely imbricate or moderately to strongly spaced, erect to patent, in this case twisted to contorted, 1--1.5 x 0.1--1.1 mm, broadly ovate-triangular to ovate, broadest at 1/7 of leaf length or more proximally, acute or gradually to abruptly shortly acuminate, rounded to base, decurrent, not or weakly plicate, margins plane or recurved proximally, serrulate or serrate almost to base; costa strong, reaching 0.6--0.8 of leaf length, ending in stout spine abaxially; juxtacostal basal cells not much differentiated from more distal cells, somewhat shorter, 10--13 \um wide, thick-walled, cells proximal to decurrency enlarged to 30 x 12--16 \um, short-rectangular, moderately thick-walled, forming a rather conspicuous, although relatively small pellucid group not reaching the leaf margin; mid leaf 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, often strongly prorate to prorate-papillose on abaxial surface. Branch leaves smaller and sometimes abruptly smaller than stem leaves and rather uniform in their own size, ovate-lanceolate, 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. 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 belong to B. hultenii. Both species are highly variable, so morphotypes at margins of ranges may have almost identical characters. The common phenotype of the species is of branch leaves rigidly spreading and markedly smaller than stem leaves, but this is not consistent, and sometimes plants are quite similar to Brachythecium rivulare; the short, usually prorate cells indicate, however, Bryhnia. Bryhnia novae-angliae is especially variable near its southern limit. Some plants in that region are little branched; others, as in North Carolina, have blunt leaves resembling Eurhynchiastrum pulchellum; they differ from this species in having flexuose and short laminal cells, 35 x 8 \um almost throughout the leaf, 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 and with rather regular pinnate branching in some places; branches to 6 mm, straight to slightly curved, terete to complanate foliate. Stem leaves closely to loosely imbricate or moderately spaced, erect-appressed, 0.7--1.2 x 0.8--1.2, often broader than long, broadly ovate-triangular, broadest at ca. 1/7 of leaf length or below, broadly acute and shortly apiculate, rounded to base, broadly and long-decurrent, strongly concave and somewhat cucullate, slightly plicate, margins plane or partially recurved, serrulate to near base; costa weak, reaching 0.4--0.7 the leaf length, lacking an abaxial spine; juxtacostal basal cells shorter and wider in 2--3 rows, indistinctly delimited from above cells, to 15 \um wide, thick-walled; cells of leaf corner and adjacent part of decurrency enlarged, up to 45 x 25 \um, forming a pellucid group of 5--7 x 8--14 cells, usually totally composed of enlarged cells, distinctly delimited from neighboring cells with a characteristic tip at leaf margin, reaching 1/2--4/5 of the distance to the costa; in mid leaf 15--40 x 6--12 \um, elongate to rhombic, strongly flexuose, thick-walled, noticeably larger in the concave basal region and much smaller distally, marginal cells average 25 x 10 \um. Branch leaves smaller, rounded-ovate, about 0.6 x 0.5 mm, with smaller cells and almost not differentiated basal cells. Sexual condition dioicous. Sporophytes not found.

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; Alaska; ne Asia.

Records of Bryhnia hultenii from eastern North America are here referred to B. novae-angliae. The appearance of B. hultenii is rather different from that of B. novae-angliae, as the stem foliage of the former looks very even and catenulate. Leaves are rather equal in size and uniformly abruptly cucullate. Microscopic characters are highly variable, although in most cases B. hultenii can be differentiated from B. novae-angliae in the sharply differentiated alar group totally composed of thin-walled pellucid cells, as well as by the costa becoming thin distally and lacking an abaxial spine, and the much less pronounced proration of the laminal cells (although in some plants of B. hultenii the laminal cells of the branch leaves are quite prorate).

OTHER LITERATURE

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

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