BFNA Title: Thuidiaceae
Author: W. R. Buck and H. A. Crum
Date: Oct. 11, 2010
Edit Level: R  
Version: 2

Bryophyte Flora of North America, Provisional Publication
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XX. THUIDIACEAE Schimper

William R. Buck

Plants small to robust, in typically stiff, dark-green to golden, loose mats. Stems creeping or ascending, mostly regularly 1--3-pinnate, not at all stipitate; without a hyalodermis, central strand small; paraphyllia present, filamentous to foliose, cells papillose; pseudoparaphyllia foliose; axillary hairs usually a single short brown basal cell and elongate hyaline distal cells, rarely (Abietinella) all cells brown. Stem and branch leaves strongly differentiated. Stem leaves mostly spreading when moist, usually broadly ovate, often abruptly acuminate, concave; margins serrulate to crenulate ± throughout, plane or recurved; costa single, strong, ending in the acumen to ± excurrent; cells quadrate to short-rectangular, 1- or pluripapillose on both surfaces or only abaxially, firm-walled; alar cells not or poorly differentiated. Branch leaves smaller than stem leaves, usually spreading, lanceolate to ovate, usually gradually acuminate to obtuse; margins serrulate to crenulate ± throughout, usually plane; costa single, weaker than in stem leaves; cells ± quadrate, 1- or pluripapillose on both surfaces or just at back, the apical cell typically truncate and pluripapillose, firm-walled, not porose; alar cells not or poorly differentiated. Specialized asexual reproduction none. Sexual condition autoicous or dioicous. Perichaetia conspicuous; leaves mostly erect, oblong-lanceolate, long-acuminate, sometimes plicate; margins subentire to long-ciliate, plane; costa single, usually strong; cells rectangular, more elongate than in vegetative leaves, usually smooth. Seta elongate, smooth to roughened, either throughout or rarely only distally, reddish. Capsule mostly inclined to horizontal, rarely erect, mostly asymmetric and arcuate, cylindric; exothecial cells thin- to thick-walled, not collenchymatous; annulus differentiated; operculum usually rostrate; peristome double, attached at the mouth, exostome teeth shouldered, bordered, externally cross-striolate basally, sometimes with overlying papillae, papillose, trabeculate internally; endostome mostly with a high basal membrane, segments keeled, not to narrowly perforate, cilia in groups of 1--3, nodulose. Calyptra cucullate, rarely mitrate, mostly naked, smooth or roughened. Spores spheric, usually papillose.

 

Genera 9, species ca. 130 (4 genera, species in the flora): cosmopolitan (but rare in Arctic), greatest occurrence in North Temperate region and southern Asia.

 

The Thuidiaceae family is characterized by pinnately branched plants with strongly differentiated branch and stem leaves. The stems are usually amply clothed with paraphyllia, but in smaller plants paraphyllia are often sparse. The leaf cells of both stem and branch leaves are short and papillose. Only Rigodium (Rigodiaceae) approaches the aspect presented by the Thuidiaceae, but it is stipitate, there are no paraphyllia, and leaf cells are smooth.

 

Haplocladium (referred here to the Leskeaceae) might be confused with various Thuidiaceae. However, in that genus the paraphyllia are not papillose (as they are throughout the Thuidiaceae) and branch leaves terminate in a smooth, sharp cell, rather than a truncate, pluripapillose cells (except in Rauiella praelonga). The Thuidiaceae were distilled to a more natural family by W. R. Buck and H. A. Crum (1990), emphasizing sexuality, placement of leaf cell papillae, papillosity of the cells of the paraphyllia, morphology of axillary hairs, and seta ornamentation. More recently, A. Touw (2001) provided a different generic scheme, which for the most part is not followed here because it seems to have been based primarily on knowledge of the Asian flora. A final resolution will require molecular study and a survey of all the taxa formerly associated with the Thuidiaceae, Leskeaceae and Anomodontaceae.

 

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. Touw, A. 2001. A review of the Thuidiaceae (Musci) and a realignment of taxa traditionally accommodated in Thuidium sensu amplo (Thuidium Schimp., Thuidiopsis (Broth.) M. Fleisch., and Pelekium Mitt.), including Aequatoriella gen. nov. and Indothuidium gen. nov. J. Hattori Bot. Lab. 90: 167--209.

 

1. Plants 1-pinnate.

2. Plants robust, erect-ascending; laminal cells stoutly 1-papillose; apex of costa of

branch leaves not covered with quadrate cells ……………………….. 1. Abietinella

2. Plants slender, creeping; laminal cells bulging, pluripapillose; apex of costa of

branch leaves covered with quadrate cells ……………………………… 3. Rauiella

1. Plants (1--)2--3-pinnate.

3. Plants robust, dioicous; paraphyllia branched; leaf cells papillose only abaxially,

usually 1-papillose; seta smooth................................................................ 4. Thuidium

3. Plants small, autoicous; paraphyllia usually unbranched; leaf cells papillose on

both free surfaces, usually pluripapillose; seta often roughened........... 2. Cyrto-hypnum

 

 

XX. Abietinella Müller Hal., Nuovo Giorn. Bot. Ital. n.ser. 3: 115. 1896 * [Latin abietis, of the conifer genus Abies, and -ella, diminutive, alluding to the habit aspect]

 

William R. Buck

 

Thuidium subgen. Abietinella (Müller Hal.) Brotherus, T. sect. Abietina Schimper

 

 

Plants relatively robust, rigid, 1-pinnate; paraphyllia filamentous to narrowly foliose, simple or branched; axillary hairs 2-celled, all cells brown. Stem leaves ovate, acuminate, plicate; margins crenulate-papillose, often recurved at least proximally; costa strong, extending ca. 3/4\x leaf length; cells rhombic to oblong-hexagonal, 1-papillose on both surfaces. Branch leaves smaller than stem leaves, ovate, acute to broadly acuminate; margins as in stem leaves but mostly plane; costa as in stem leaves; cells rounded-quadrate to short-rectangular, 1-papillose on both surfaces except terminal laminal cell pluripapillose. Sexual condition dioicous. Perichaetial leaves strongly differentiated, erect, oblong-lanceolate, long-acuminate; margins serrate to serrulate above; costa subpercurrent; cells elongate, thick-walled, porose. Seta elongate, slender, smooth. Capsule inclined, strongly curved, cylindric; annuli differentiated in 2--3 rows; annuli not seen; opercula obliquely short-rostrate; peristomes hypnoid with endostomial segments narrowly perforate and cilia 1--2. Calyptra cucullate, naked.

 

Species 3 (1 in the flora): North America, Europe, Asia.

 

Abietinella is an easy genus to recognize in the flora. It is characterized by relatively robust, stiff, more or less erect, once-pinnate, paraphylliate stems, often golden-brown, growing most often on fairly dry, mostly calcareous sands.

1. Abietinella abietina (Hedwig) M. Fleischer, Musci Fl. Buitenzorg 4: 1497. 1923 F

 

Hypnum abietinum Hedwig, Sp. Musc. 353. 1801; Thuidium abietinum (Hedwig) Schimper

 

Plants dark-green, yellowish or dark brown, sometimes blackish-tinged. Stems to 12 cm, erect-ascending; branches short, unequal, tapered; paraphyllia abundant. Stem leaves erect when dry, erect-spreading when moist, 1.2--1.8 mm, orange at the insertion; cells stoutly 1-papillose over the lumina. Branch leaves erect when dry, erect-spreading when moist, 0.6--0.7 mm. Perichaetial leaves to 4 mm, long-acuminate, distal margins strongly serrate. Seta 2--2.5 cm; capsules 2--3 mm, yellow-brown. Spores 9--11 \um, finely papillose.

 

Capsules very rare, maturing late summer. Dry, exposed calcareous rocks and soil, sand of partially stabilized dunes, among talus at base of cliffs, and humus in open, coniferous forests; low to moderate elevations; Greenland; Alta., B.C., Man., N.B., Nfld. and Labr. [Nfld.], N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon; Alaska, Ariz., Colo., Conn., Iowa, Maine, Mich., Minn., Mo., Mont., N.H., N.J., N.Mex., N.Y., N.Dak., Pa., S. Dak., Va., Vt., Wis., Wyo.; Europe; Asia.

 

Abietinella abietina is the easiest of the Thuidium-like plants to recognize in our flora, in part

because of the distinctive habitat requirements. The stems are once-pinnate, erect-ascending and often occur in extensive, lax mats. Paraphyllia are abundant on stems and branches, but are usually not nearly as strongly branched as in Thuidium s.str. It is widespread throughout the northern part of our range. Unlike Thuidium, Abietinella is papillose on both leaf surfaces rather than just the back.

 

2. CYRTO-HYPNUM (Hampe) Hampe & Lorentz in G. Hampe, Bot. Zeit. 27: 455. 1869 * [Greek cyrto, curved or arched, and hypnum, lichen, or by usage, pleurocarpous moss]

                                                                                                                                   William R. Buck

 

Hypnum subg. Cyrto-hypnum Hampe, Flora 50: 78. 1867; Thuidium sect. Minutula Schimper; T. subg. Microthuidium Limpricht

 

Plants small and slender, 1--2-pinnate; paraphyllia filamentous, unbranched; axillary hairs 2-celled.  Stem leaves broadly triangular to broadly ovate, acuminate; margins crenulate-papillose, often recurved at least basally; costa strong, extending 4/5\x leaf length to subpercurrent; cells ± quadrate, pluripapillose [1-papillose] on both surfaces, usually with the papillae arranged around the periphery of the lumina.  Branch leaves typically smaller than stem leaves, ovate to oblong-ovate, obtuse to short-acuminate; margins as stem leaves but plane; costa strong, ending 3/4--7/8\x leaf length, sometimes crested or the apex projecting as a small spine; cells similar to those of stem leaves.  Sexual condition autoicous.  Perichaetial leaves strongly differentiated, erect, oblong-lanceolate to oblong-ovate, acuminate; margins entire to ciliate; costa percurrent to excurrent.  Seta slender, smooth or papillose. Capsule inclined to horizontal, cylindric; annulus differentiated in 2--3 rows; operculum obliquely long-rostrate; peristome hypnoid with endostomial segments not or narrowly perforate and cilia 1--3.  Calyptra cucullate, naked.

 

Species 30--40 (4 in the flora): mostly tropical.

 

SELECTED REFERENCE  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. Michigan Herb. 17: 55--69.

 

1. Stems 1-pinnate; branch and stem leaves of about the same size, more than 0.4 mm, strongly incurved when dry . . . . 1. Cyrto-hypnum involvens

 

1. Stems 2-pinnate (sometimes inconspicuous); branch leaves smaller than stem leaves, less than 0.4 mm, erect to somewhat but not strongly incurved when dry.

 

2. Stems and branches as well as the paraphyllia papillose  . . . . 2. Cyrto-hypnum pygmaeum

 

2. Stems and branches with papillose paraphyllia, but not papillose themselves.

 

3. Stems weakly and irregularly 2-pinnate; cells of paraphyllia mostly twice as long as wide; seta smooth; perichaetial leaves serrulate  . . . . 3. Cyrto-hypnum minutulum

 

3. Stems regularly 2-pinnate; cells of paraphyllia mostly quadrate; seta rough; perichaetial leaves ciliate . . . . 4. Cyrto-hypnum schistocalyx

 

1. Cyrto-hypnum involvens (Hedwig) W. R. Buck & H. A. Crum, Contr. Univ. Michigan Herb. 17: 66. 1990

 

Leskea involvens Hedwig, Sp. Musc. Frond, 218. 1801; Thuidium involvens (Hedwig) Mitten

 

Stems 1-pinnate, smooth; paraphyllia to ca. 8 cells in length, cells ca. 1:1, all sparingly papillose.  Stem leaves flexuose-incurved when dry, ovate-triangular, (0.3--)0.5--0.6 mm, ± abruptly short-acuminate; costa disappearing in the acumen but not filling it.  Branch leaves strongly incurved when dry, ± 2-ranked, often laxly disposed, ca. 0.5 mm, obtuse to acute; costa ca. 7/8\x leaf length, often ± flexuose, not covered with quadrate cells.  Perichaetial leaves laxly serrulate distally, subentire proximally or with a few coarse, blunt teeth.  Seta papillose throughout. Capsule with endostomial cilia single, rarely with rudimentary additional cilium.

 

Capsules mature Nov.--Dec.(--Mar.).  Lowland, moist forests, growing over limestone, soil, humus, rotten wood; 0 m; s Fla.; Mexico, Central America, West Indies; n South America.

 

The once-pinnate stems, strongly incurved leaves, non-ciliate perichaetial leaves and rough seta distinguish Cyrto-hypnum involvens. The aspect is quite different from the other species in the genus. It occurs between 0 and 1000 m south of the flora area.

 

2. Cyrto-hypnum pygmaeum (Schimper) W. R. Buck & H. A. Crum, Contr. Univ. Michigan Herb. 17: 67. 1990

 

Thuidium pygmaeum Schimper in P. Bruch, W. P. Schimper & W. Gümbel, Bryol. Eur. 5(fasc. 49/51): 162. 1852

 

Stems 2-pinnate, stems and branches papillose; paraphyllia (1--)2--4(--5) cells in length, cells ca. 1:1, all strongly papillose.  Stem leaves slightly incurved when dry, ovate-triangular, 0.2--0.35 mm, acuminate; costa about 3/4\x leaf length.  Branch leaves erect-incurved when dry, 0.2--0.3 mm on primary branches, ca. 0.15 mm on secondary branches, acute to short-acuminate; costa 1/2--3/5\x leaf length, straight, not covered with quadrate cells.  Perichaetial leaves serrulate distally, subentire proximally.  Seta smooth. Capsule with endostomial cilia in pairs.

 

Capsules mature July--Sept.  Moist woods, growing over moist rocks, usually limestone but less often sandstone and quartzite; mostly at moderate to low elevations; Ont., Que.; Ala., Ark., Conn., Fla., Ga., Ill., Ind., Iowa, Ky., Mass., Mo., N.C., N.J., N.Y., Ohio, Okla., Pa., Tenn., Va., Vt. Wis.; Asia (China, Japan, Korea).

 

Cyrto-hypnum pygmaeum is the flora’s smallest species of Cyrto-hypnum.  The diminutive stature coupled with papillose stems and branches is distinctive.  It is most likely confused with Heterocladium macounii, which also has pluripapillose leaf cells and papillose stems and branches.  However, that species is larger and has a costa ending near or before mid leaf and is without paraphyllia; although pseudoparaphyllia are present, these have pointed terminal cells, not truncate as are the paraphyllia of C. pygmaeum.

 

3. Cyrto-hypnum minutulum (Hedwig) W. R. Buck & H. A. Crum, Contr. Univ. Michigan Herb. 17: 66. 1990

 

Hypnum minutulum Hedwig, Sp. Musc. Frond., 260. 1801; Thuidium minutulum (Hedwig) Schimper

 

Stems weakly and irregularly 2-pinnate, smooth; paraphyllia 2--3(--5) cells in length, cells mostly ca. 2:1, usually only the terminal one papillose.  Stem leaves erect-incurved when dry, broadly ovate, 0.3--0.45(--0.55) mm, ± abruptly shortly and broadly acuminate; costa ending about 4/5\x leaf length.  Secondary branch leaves erect-incurved when dry, 0.15--0.25 mm, acute; costa ending ca. 3/4\x leaf length, straight, apical portions often covered with quadrate cells and thus projecting as low crests.  Perichaetial leaves serrulate distally, subentire basally.  Seta smooth. Capsule with endostomial cilia 1--2(--3). 

 

Capsules mature Feb.--Aug.(--Oct.).  Moist woods, usually growing on rotten logs, sometimes on rock, especially limestone, and bases of trees; mostly moderate to low altitudes; Ont., N.B.,; Ala., Ark., Conn., Fla., Ga., Ill., Ind., Iowa, La., Maine., Md., Mich., Minn., Mo., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va.; Mexico, Central America,  n,c South America; West Indies; Europe.

 

Because of its wide range in eastern North America, Cyrto-hypnum minutulum  is often confused with others in the family. In the southernmost part of the flora range, C. involvens may be distinguished by quadrate-celled paraphyllia and a rough seta.  Cyrto-hypnum pygmaeum is more delicate with elaborate branching, with leaves when dry erect rather than ± incurved, and with papillose branches and stems.  Rauiella scita has leaf cells strongly bulging, is more robust, 1-pinnate with larger, quadrate-celled paraphyllia, and has longer acuminate stem leaves.  All the true Thuidia have branched paraphyllia and cells papillose only at back.  Species of Haplocladium have leaf cells 1-papillose.  Similarly, Helodium blandowii has 1-papillose leaf cells and its paraphyllia are branched and long-celled.

 

4. Cyrto-hypnum schistocalyx (Müller Hall.) W. R. Buck & H. A. Crum, Contr. Univ. Michigan Herb. 17: 67. 1990

 

Hypnum schistocalyx Müller Hall., Syn. Musc. Frond. 2: 691. 1851; Thuidium schistocalyx (Müller Hall.) Mitten

 

Stems regularly 2-pinnate, smooth; paraphyllia 2--8 cells in length, cells mostly 1:1, all papillose.  Stem leaves appressed when dry, broadly triangular, (0.2--)0.25--0.32(--0.5) mm, gradually and broadly acuminate, sometimes piliferous; costa ending ca. 5/6 the leaf length.  Secondary branch leaves incurved-appressed when dry, 0.15--0.25(--0.3) mm, acute to obtuse; costa ending ca. 3/4\x leaf length, straight, apical portions often covered with quadrate cells and thus projecting as low crests.  Perichaetial leaves strongly flexuose-ciliate.  Seta papillose throughout; endostomial cilia 1(--2).

 

Capsule maturity not determined. Moist forests, usually growing on limestone or bases of trees; 0 m; Fla. (Dade Co.); Mexico, Central America; n South America; West Indies.

 

The ciliate perichaetial leaves and roughened seta characterize Cyrto-hypnum schistocalyx, an essentially tropical taxon.  Cyrto-hypnum schistocalyx occurs from sea level to 200 m south of the flora area.

 

3. Rauiella Reimers, Hedwigia 76: 287. 1937 * [For Eugene Abraham Rau, 1848--1932, American bryologist, and Latin -ella, diminutive]

 

William R. Buck

 

Plants mostly medium-sized, 1-pinnate; stems creeping, the branches prostrate to ascending; paraphyllia ± filamentous, mostly unbranched, abundant on stems, sparse on branches; axillary hairs 3-celled.  Stem leaves broadly ovate, abruptly long-acuminate, concave, somewhat decurrent; margins crenulate to crenulate-papillose, plane or recurved; costa strong, ending near base of the acumen, the apical portion not covered with short cells; cells ± quadrate, bulging on both surfaces, pluripapillose (or rarely 1-papillose) on both surfaces, with the papillae clustered over the lumina or arranged around the periphery.  Branch leaves smaller than stem leaves, ovate to, gradually broadly acuminate; margins as stem leaves; costa strong, ending well beyond midleaf, covered distally with short laminal cells; cells similar to those of stem leaves.  Sexual condition autoicous.  Perichaetial leaves enlarged, mostly erect, mostly lanceolate, long-acuminate, ± plicate; margins crenulate, never ciliate; costa subpercurrent; cells more elongate than in vegetative leaves, often smooth.  Seta elongate, smooth. Capsule suberect to horizontal, short-cylindric, arcuate; annuli differentiated in 2--3 rows; opercula stoutly and obliquely apiculate to rostrate; peristomes hypnoid with endostomial segments not or narrowly perforate and cilia 1--3.  Calyptra cucullate, naked.

 

Species 8 (2 in the flora): North America, Central and South America, Africa, Asia.

 

Rauiella has frequently been misunderstood, being confused with Thuidium and Haplocladium. It is characterized in the flora region by leaf pluripapillose on both sides of the leaf, by well-developed papillose paraphyllia of oblate cells on the stems (sparse on the branches), a smooth seta, and autoicous sexuality. The distal part of the costa on branch leaves are covered by laminal cells (as seen in Cyrto-hypnum), but in Rauiella the cells are also bulging on both surfaces (but flat in Cyrto-hypnum).

 

SELECTED REFERENCE Reimers, H. 1937. Die europäischen Haplocladium-Arten mit besonderer Berücksichtigung ihrer aussereuropäischen Verbreitung und ihrer Verwandtschaft. Hedwigia 76: 191--298.

 

1. Apical cell of branch leaves pointed, not papillose; southwestern ... 1. Rauiella praelonga

1. Apical cell of branch leaves pluripapillose; eastern........... 2. Rauiella scita

 

1. Rauiella praelonga (Bescherelle) Wijk & Margadant, Taxon 11: 222. 1962  F

 

Pseudoleskea praelonga Schimper ex Bescherelle, Mém. Soc. Sci. Nat. Cherbourg 16: 233. 1872; Bryohaplocladium praelongum (Bescherelle) H. A. Crum; Haplocladium praelongum (Bescherelle) H. A. Crum; Rauia praelonga (Bescherelle) Brotherus

 

Stems 2--3(--6) cm, ± regularly 1-pinnate, the branches to ca. 1 cm, mostly shorter; paraphyllia mostly filamentous, 1-seriate distally and 2(--3)-seriate proximally, mostly unbranched, the cells oblate, papillose.  Stem leaves erect when dry, spreading to wide-spreading when moist, broadly ovate, 0.5--0.6 mm, abruptly acuminate; margins plane in the acumen, mostly recurved proximally, rarely erect; costa ending near base of the acumen, pellucid; cells quadrate to isodiametric, ca. 5--6 \um wide, pluripapillose on both surfaces, with 3--5 papillae mostly around the periphery of the lumina.  Branch leaves erect when dry, spreading to wide-spreading when moist, ovate, ca. 0.4 mm, gradually broad-acuminate; margins plane to irregularly recurved; costa ca. 4/5\x leaf length, pellucid proximally, obscure distally by overlying laminal cells; cells quadrate to isodiametric, with 4--6 papillae mostly around the periphery of the lumina, ca. 5--6 \um wide, the apical cell enlarged, pellucid and smooth, pointed.  Perichaetial leaves ca. 2.5 mm, lanceolate, long-acuminate, plicate; costa subpercurrent; cells rectangular to long-rectangular, smooth.  Seta smooth, 1--1.5 cm; operculum stoutly apiculate; segments not or narrowly perforate, cilia in groups of 1--2. Spores ca. 17 \um, finely papillose.

 

Dead branches and rocks, probably in mostly exposed habitats; ca. 1200 m; Ariz.; Mexico; West Indies; Central America; South America; e,s Africa.

 

            Rauiella praelonga, only occurring rarely, in the southwestern part of our flora, differs from R. scita by the shorter acumen of the stem leaves and the nonpapillose apical cell of the branch leaves.

 

2. Rauiella scita (Palisot de Beauvois) Reimers, Hedwigia 76: 287. 1937.   E

 

Hypnum scitum Palisot de Beauvois, Prodr. Aethéog. 69. 1905; Rauia scita (Palisot de Beauvois) Austin; Rauiella scita var. aestivalis (Austin) Wijk & Margadant; Thuidium scitum (Palisot de Beauvois) Austin/ Thuidium scitum var. aestivale Austin

 

Stems 4--6 cm, ± regularly 1-pinnate, the branches 2--3 mm; paraphyllia mostly filamentous, 1-seriate distally and 2(--3)-seriate proximally, weakly branched, the cells oblate, papillose.  Stem leaves erect when dry, erect-spreading when moist, broadly ovate to cordate-deltoid, 0.5--0.6 mm, narrowly long-acuminate, not to moderately 2-plicate; margins plane distally, loosely revolute proximally; costa ending near base of the acumen, pellucid; cells rounded hexagonal, ca. 5--6 \um wide, pluripapillose on both surfaces, with 3--6 papillae mostly around the periphery of the lumina.  Branch leaves appressed when dry, erect-spreading when moist, ovate, ca. 0.4 mm, acute; margins plane to irregularly recurved; costa ca. 4/5\x leaf length, pellucid below, obscure distally by overlying laminal cells; cells quadrate to isodiametric, with 4--6 papillae mostly around the periphery of the lumina, ca. 5--6 \um wide, the apical cell truncate, pluripapillose.  Perichaetial leaves ca. 1.5 mm, lanceolate, long-acuminate, erect, plicate; costa subpercurrent; cells rectangular to long-rectangular, smooth.  Seta smooth, 1--2 cm; operculum obliquely stoutly short-rostrate; segments narrowly perforate, cilia in groups of 2--3. Spores 10--13 \um, finely papillose.

 

            Capsules mature fall--early winter. Bark, especially at bases of hardwoods, mature forests; mostly moderate elevations; N.B., N.S., Ont., Que.; Conn., D.C., Del., Ind., Iowa, Ky., Maine, Mass., Md., Mich., N.C., N.H., N.J., N.Y., Ohio, Pa., R.I., Tenn., Va., Vt., Wis., W.Va.

 

            Rauiella scita is most likely confused with a Leskea rather than the other Thuidiaceae. However, the abundant paraphyllia and pluripapillose laminal cells will immediately separate it from that genus. Like R. praelonga, the distal portion of the costa of the branch leaves is covered with laminal cells, but in R. scita the apical cell of the branch leaves is truncate and pluripapillose, unlike the smooth, pointed apical cell in R. praelonga.

 

 

4. THUIDIUM Bruch & Schimper in P. Bruch, W. P. Schimper & W. Gümbel, Bryol. Eur. 5: 157. 1852 (fasc. 40--51 Mon. 1) * [Alluding to branched habit of Thuja]

 

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 Eastern North America. Vol. 2, pp. 894--911. New York.

 

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 pluripapillose.

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 delicatulum

 

 

1. Thuidium tamariscinum (Hedwig) Bruch & Schimper in P. Bruch, W. P. Schimper & W. Gümbel, Bryol. Eur. 5: 163 (fasc. 49--51 Mon. 7. 2, 3). 1852

 

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 (Jamaica); Europe; Asia (e Russia in Sakhalin, Japan).

 

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 Atlantic and Gulf Coastal Plains and the Mississippi Embayment. This species is slender, and loosely, sometimes irregularly         2-pinnate. It could easily be taken for a depauperate expression of Thuidium delicatulum. However, it is smaller and has short-pointed stem leaves with margins plane or nearly so and the branch leaves are noticeably incurved. The leaf cells are adorned with very low papillae that are generally forked so that the cells commonly appear in surface view to be 2(--3)-papillose .

 

4. Thuidium delicatulum (Hedwig) Bruch & Schimper in P. Bruch, W. P. Schimper & W. Gümbel, Bryol. Eur. 5: 164, fig. 484. (fasc. 49--51 Mon. 8, fig. 4). 1852

 

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. delicatulum

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 delicatulum var. delicatulum

 

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. 1965 (1966)

 

Thuidium recognitum var. radicans Kindberg, Rev. Bryol. 19: 103. 1892; T. philibertii  Limpricht; T. recognitum ssp. philibertii (Limpricht) Dixon

 

Stem leaves somewhat longer, 1--1.5 mm, averaging 1.2 mm, ending in a hyaline point of 2--8 1-seriate cells. 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., Man., Nfld., N.S., Yukon; Alaska, Iowa, Maine, Mich., Minn., N.J., N.Mex., N.Y., S.C., S.Dak., Va., Wis.; Mexico; South America (Peru); Europe; Asia.

 

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.