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BFNA
Title: Thuidium |
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Edit Level R XX. THUIDIUM Bruch & Schimper in P. Bruch, W. P.
Schimper & Howard A. Crum Plants usually
relatively large, in dull, green to yellow-brown mats. Stems creeping to arched-ascending, 2--3-pinnate, and usually
frondose; paraphyllia abundant, especially on stems, lanceolate or
filiform-branched, papillose. Stem and
branch leaves dimorphic. Stem
leaves ovate, acuminate, generally +/- plicate at base; margins usually
revolute to the base of the acumen; margins papillose-serrulate proximally,
often serrulate distally by projecting cell ends; costa ending before the
apex; cells mostly +/- uniform throughout, rounded- to oblong-hexagonal,
thick-walled, coarsely 1-papillose at back (or less commonly with low, forked
papillae and appearing to be pluripapillose). Primary branch leaves often rather similar to stem leaves but
shorter. Secondary and tertiary branch
leaves much smaller, concave, ovate, acute, with erect margins and
usually ending in a truncate, pluripapillose cell; costa shorter and weaker. Sexual condition dioicous. Perichaetial
leaves +/- elongate, erect, pale, lanceolate or ovate- lanceolate, long-acuminate, sometimes
ciliate-margined; costa ending near the apex; cells elongate, smooth or
somewhat papillose. Seta elongate,
smooth or rarely papillose. Capsule inclined
to horizontal, curved-cylindric, asymmetric, smooth; annulus of 2--4
irregular layers of small cells, often tardily deciduous; operculum conic or
rostrate from a convex-conic base; stomata present in the short neck;
peristome teeth yellow, yellow-brown, or red-brown, densely cross-striolate
basally; endostome consisting of a high basal membrane, keeled segments, and
nodulose cilia in groups of 2--4. Calyptra
cucullate, smooth, naked. Species 229 (4 in the flora); almost worldwide. SELECTED REFERENCES
Buck, W. R. and H. A. Crum. 1990. An evaluation of familial limits among
the genera traditionally aligned with the Thuidiaceae and Leskeaceae. Contr.
Univ. Mich. Herb. 17: 55--69. Crum, H. & L. E. Anderson. 1981. Mosses of Thuidium is characterized by abundant, 2--3-pinnate branching paraphyllia; dioicous sexuality; dimorphic stem and branch leaves with short, thick-walled cells that are papillose abaxially and nearly always 1-papillose; 3-celled axillary hairs with a single, short, brown basal cell and two elongate, hyaline ones; terminal cells of branch leaves mostly truncate and pluripapillose; and setae nearly always smooth . The genus is treated here in a sense exclusive of Abietinella, Rauiella, and Cyrto-hypnum (cf. W. R. Buck and H. A. Crum 1990). Abietinella is relatively robust and has 1-pinnate branching, abundant paraphyllia, dioicous inflorescences, leaf cells 1-papillose on both surfaces, and 3-4-celled, brown axillary hairs. Rauiella and Cyrto-hypnum are small plants with autoicous inflorescences, paraphyllia short and not much branched, and leaf cells papillose on both surfaces (most commonly pluripapillose). Rauiella has 1-pinnate branching, 3-celled axillary hairs, leaves not incurved when dry, strongly bulging leaf cells, and smooth setae. Cyrto-hypnum has mostly 2-pinnate branching, as well as 2-celled axillary hairs, leaves incurved when dry, leaf cells plane, and setae often roughened. 1. Branching mostly 3-pinnate; terminal cells of branch leaves acute, smooth. . . . . 1. Thuidium tamariscinum 1. Branching mostly 2-pinnate; terminal cells of branch leaves truncate and plurpapillose. 2. Stem leaves incurved at base
and spreading at the tips when dry, distinctly plicate; costa nearly filling
the acumen; paraphylla papillose at cell ends. . .
. 2. Thuidium
recognitum 2. Stem leaves ± erect, less markedly plicate; costa not filling the acumen; paraphylla papillose at cell midpoints. 3. Stem leaves short-pointed,
with plane margins or sometimes revolute at base; cells with low, forked
papillae and appearing 1--3-papillose. . . . 3. Thuidium allenii 3. Stem leaves acuminate,
revolute-margined; cells coarsely 1-papillose, sometimes forked but not
appearing pluripapillose. . . 4. Thuidium 1. Thuidium tamariscinum
(Hedwig) Bruch & Schimper in P. Bruch, W. P. Schimper & Hypnum tamariscinum Hedwig, Sp. Musc. Frond., 261. 1801 Plants vivid-green to yellowish. Stems up to 15 cm, creeping or arched, (2--)3-pinnately branched and frondose; paraphyllia papillose near the middle of cells. Stem leaves loosely erect when dry, erect-spreading when moist, 1.5--2 mm, broadly ovate, gradually to rather abruptly acuminate, plicate; margins revolute to the base of the acumen, denticulate distally; costa strong, ending near the leaf apex; cells rounded to elliptic, thick-walled, 13--20 x 8--10 \um, stoutly 1-papillose. Branch leaves ending in a sharp, smooth cell. Primary branch leaves somewhat resembling stem leaves, ca. 0.8 mm, 2-plicate; margins somewhat recurved proximally; costa delicate, ending before the apex. Secondary and tertiary branch leaves to about 0.4 mm, ovate, acute, with erect margins and a weak costa ending near leaf middle; cells stoutly 1-papillose, the papillae +/- curved. Perichaetial leaves pale yellow, ca. 3 mm, oblong-lanceolate, long-subulate, serrate distally, long-ciliate proximally; costa ending in the subula. Seta 25--45 mm. Capsule 3--4 mm; operculum 1.8 mm, obliquely long-rostrate; cilia of endostome 3--4. Spores ca. 12 \um, smooth or very finely papillose. Moist soil or soil over rocks, sometimes in stream beds;
Nfld.; West Indies ( Thuidium tamariscinum is a woodland species of relatively large and elegantly frondose plants. The branching is typically tripinnate, but it is sometimes bipinnate or imperfectly tripinnate. The leaf cells are stoutly 1-papillose, except that the terminal cell of branch leaves is sharp and smooth. 2. Thuidium recognitum (Hedwig) Lindberg, Not. Sällsk. F. Fl. Förh. 13: 416. 1874 Hypnum recognitum J. Hedwig, Sp. Musc. Frond., 261. 1801; H. protensum Michaux Plants in light-green to yellowish or brownish mats. Stems 4--9 cm, 2-pinnately branched and frondose; paraphyllia papillose mostly at or near cell ends, the terminal cell usually with 2--3 large, divergent papillae. Stem leaves spreading with reflexed tips when moist, +/- incurved at base and wide-spreading at the tips when dry, ca. 1 mm, broadly ovate, abruptly acuminate, distinctly plicate; margins papillose-serrulate, more strongly so in the acumen, plane at least when removed from the stem, rarely +/- revolute proximally; costa broadened distally, nearly filling the acumen but disappearing near the apex; distal cells to 24 x 8--10 \um, rhombic to oblong-rhombic, coarsely 1-papillose. Branch leaves ending in a truncate, pluripapillose cell. Primary branch leaves smaller, with a shorter costa. Secondary branch leaveses ca. 0.2 mm, erect-spreading when wet or dry, ovate, acute; costa 1/3--2/3 the leaf length; distal cells rhombic, 8--12 x 8--10 \um, thick-walled, stoutly 1-papillose, the papillae somewhat curved, the terminal cell truncate, pluripapillose. Perichaetial leaves up to 4.2 mm; margins denticulate, sometimes dentate or notched near base of the acumen. Seta 20--42 mm, reddish. Capsule 2--3.5 mm; operculum 0.7--1 mm, high-conic or bluntly short-rostrate; cilia of endostome in 2's and 3's. Spores 11--16 \um, smooth or nearly so. Moist soil, humus, or rocks, infrequently on logs or bark at base of trees, calcareous habitats, woodlands, often in clearings and timber trails; Alta., B.C., Man., Ont., Que.; Alaska, D.C., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., Ohio, Okla., Oreg., Pa., Tenn., Vt., Va., Wash., W.Va., Wis.; Europe. The specific epithet of Thuidium recognitum was applied by Hedwig because he recognized the many differences that separate the species from T. delicatulum: stem leaves that are shortly, broadly, and abruptly acuminate and plicate, with margins plane or nearly so; and costa spreading out and nearly filling the acumen; tips of the stem leaves wide-spreading from an arched and incurved base; perichaetial leaves eciliate; paraphyllia papillose at or near cell ends; and operculum not or only shortly and bluntly rostrate. 3. Thuidium allenii Austin, Bull. Torrey Bot. Club 7: 16. 1880 Thuidium glaucinum var. ludovicianum Cardot, Bryologist 8: 51. 1905 Plants slender, light-green or yellow. Stems loosely branched, irregularly to regularly 2-pinnate, loosely foliate; paraphyllia papillose at the side of cells. Stem leaves erect-spreading when moist, loosely erect or slightly incurved when dry, ca. 1 mm, ovate, broadly short-pointed, acute, not or somewhat plicate; margins +/- denticulate all around because of projecting cell ends, plane or sometimes reflexed near the base; costa ending near the apex; distal cells hexagonal, mostly about 7 \um, moderately thick-walled, 1-papillose, the papillae low and usually forked thus appearing to be 1--3 per cell. Branch leaves ending in a truncate, pluripapillose cell. Primary branch leaves strongly incurved, 0.5--0.6 mm, ovate, acute; costa 8/10--9/10 the leaf length; cells 8--9 \um. Secondary branch leaves similar to those of primary branches but smaller, 0.2--0.4 mm, acute or obtuse; costa 7/10--8/10 the leaf length. Perichaetial leaves eciliate. Seta 25--30 mm. Capsule ca. 2.5 mm; operculum bluntly conic. Spores not seen. Uncommon, soil, logs, exposed roots, tree bases in swamps, often just above water line, characteristically in Taxodium-Nyssa-Chamaecyparis swamps; Ala., Ark., Conn., Del., Fla., Ga., Ind., La., Md., Mass., Miss., N.Y., N.C., Pa., Tenn., Tex., Va. Thuidium
allenii
is essentially restricted to the 4. Thuidium delicatulum (Hedwig)
Bruch & Schimper in P. Bruch, W. P. Schimper & Hypnum delicatulum Hedwig, Sp. Musc. Frond., 160. 1801; Thuidium recognitum var. delicatulum (Hedwig) Warnstorf Plants green or yellowish. Stems 3--8 cm, 2--3-pinnate, ± frondose; paraphyllia mostly papillose at cell points. Stem leaves erect-spreading when moist, appressed when dry, 0.6--1.5 mm, triangular-ovate, gradually or abruptly narrowed to a broad acumen or ending in a hyaline point of 2--8 1-seriate cells, not plicate; margins papillose-serrulate, revolute from the insertion to the acumen; costa ending well before the apex; distal cells irregularly oblong-hexagonal, 6--10 x 8--12 \um, rhombic, moderately thick-walled, coarsely 1-papillose. Branch leaves ending in a truncate, pluripapillose cell. Primary branch leaves erect-spreading, to 0.5 mm, acute; costa 1/2--2/3 the leaf length; cells 6--8 x 8--12 \um, rhombic, coarsely 1-papillose, the papillae curved, sometimes forked. Secondary branch leaves similar but smaller. Perichaetial leaves to 5 mm, eciliate to ciliate proximally, often denticulate distally. Seta 15--45 mm. Capsule 1.8--4 mm; operculum 0.7--2 mm, long-rostrate; cilia of endostome in 2's and 3's. Spores 12--24 \um, smooth. Common in woodlands, soil, humus, rocks, logs, and stumps, infrequently bases of trees; Alta., B.C., Man., N.B., Nfld., N.S., Ont., Que., Yukon; Ala., Alaska, Ariz., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky, La., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis.; Mexico; Central America; n South America; Europe; Asia. Thuidium delicatulum, needlessly confused with T. recognitum, can be recognized by stem leaves erect or erect-spreading when moist, not plicate and rather gradually acuminate, with margins recurved to the base of the acumen and costa ending well before the apex. The paraphyllia have small papillae along the cell midpoints. The leaf cells are stoutly 1-papillose, but often, especially in the South, the papillae are forked. The operculum is long-rostrate . 1. Stem leaves merely acute; perichaetial leaves ciliate. . . 4a. Thuidium delicatulum var.
1. Stem leaf apex extending by 2--8 hyaline cells in a
single row; perichaetial leaves not ciliate or rarely ± so. . . . 4b. Thuidium delicatulum
var. radicans 4a. Thuidium Stem leaves somewhat shorter, 0.6--1.4 mm, averaging 0.9 mm, acute and not ending in a hyaline point 1-seriate cells. Perichaetial leaves ciliate proximally, denticulate distally. Common in woodlands, soil, humus, rocks, logs, and stumps, infrequently bases of trees; N.B., N.S., Ont., Que.; Ala., Ariz., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky, La., Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.; Mexico; Central America; n South America; Europe. Thuidium delicatulum var.
delicatulum is apparently more often in acid
substrates than is T. recognitum and T. delicatulum var. radicans. The perichaetial leaves are copiously
ciliate. 4b. Thuidium delicatulum var. radicans (Kindberg) H. A. Crum, Steere & L. E. Anderson, Bryologist 68: 434. 1966 (1965) Thuidium
recognitum
var. radicans
Kindberg, Rev. Bryol. 19: 103. 1892; T.
philibertii Limpricht; T. recognitum ssp. philibertii (Limpricht) Stem leaves somewhat longer, 1--1.5 mm, averaging 1.2 mm, ending in a hyaline point of 2--8 cells in 1 row. Perichaetial leaves usually not ciliate but sometimes sparsely so, rarely copiously ciliate. Apparently a calciphile, soil, humus, rocks, or logs in
swampy places; Alta., B.C., Ont., The var. radicans intergrades with the var. delicatulum. The annulus of the var. radicans is of 2--3 rows of cells scarcely differentiated from suboral cells and is sometimes of aid in distinguishing this variety from var. delicatulum.
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