BFNA Title: Cyrto-hypnum
Author: W. R. Buck
Date: April 24, 2003
Edit Level: R  Brum+
Version: 1

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden
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St. Louis, MO 63166-0299 USA
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Thuidiaceae -Cyrto-hypnum

 

X. CYRTO-HYPNUM (Hampe) Hampe & Lorentz in 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 below; costa strong, extending 4/5 the leaf length to subpercurrent; cells ± quadrate, pluripapillose (or 1-papillose extralimitally) 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 the 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. Capsules 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, larger 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. 218. 1801; Thuidium involvens (Hedwig) Mitten

 

Stems 1-pinnate, smooth; paraphyllia to ca. 8 cells long, cells ca. 1:1, all sparingly papillose.  Stem leaves flexuosely 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 the leaf length, often ± flexuose, not covered with quadrate cells.  Perichaetial leaves laxly serrulate above, subentire below or with a few coarse, blunt teeth.  Seta papillose throughout; endostomial cilia single, rarely with rudimentary additional one.

 

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

 

The once-pinnate stems, strongly incurved leaves, non-ciliate perichaetial leaves and rough seta are distinctive. 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 long, 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 the 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 the leaf length, straight, not covered with quadrate cells.  Perichaetial leaves serrulate above, subentire below.  Seta smooth; 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).

 

This is our 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 below midleaf and is without paraphyllia; although there are pseudoparaphyllia they have pointed terminal cells, not truncate as in 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 long, 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 the leaf length.  Secondary branch leaves erect-incurved when dry, 0.15--0.25 mm, acute; costa ending ca. 3/4 the leaf length, straight, apical portions often covered with quadrate cells and thus projecting as low crests.  Perichaetial leaves serrulate above, subentire below.  Seta smooth; endostomial cilia 1--2(--3). 

 

Capsules mature Feb.--Aug.(--Oct.).  Moist woods, usually growing on rotten logs, but 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., Md., Me., Mich., Minn., Mo., N.C., N.J., N.Y., Ohio, Pa., S.C., Tenn., Va., W.Va.; Mexico, Central America,  n and c South America; West Indies; Europe.

 

Because of its wide range in eastern North America, this species is often confused with others in the family.  In the southernmost part of its North American 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 and 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 long, 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 the 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 this species of the American tropics.  It is closely related to Cyrto-hypnum scabrosulum (Mitten) Buck & Crum, but that species has branch leaves more laxly disposed and perichaetial leaves not or scarcely ciliate. Cyrto-hypnum schistocalyx occurs from sea level to 200 m south of the flora area.