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Dicranum scoparium

(Dicranum Moss)

Overview

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Common Names

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Common Names in English:

Dicranum Moss

Description

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Family Dicranaceae

Plants small to large, often in dense tufts. Stems erect , simple or dichotomously to irregularly branched, usually with central strand, often densely radiculose , tips occasionally deciduous. Leaves in several rows around the stem, erect or secund , often falcate-secund, sometimes crispate , short- to long-lanceolate, whole leaves or their tips sometimes deciduous; costa single, usually strong , percurrent to excurrent, sometimes ending in a short to long hyaline awn , smooth , ridged or lamellose on abaxial surface, rhizoids occasionally on adaxial or abaxial surface near leaf base ; laminal cells smooth or sometimes distal cells mammillose or papillose on one or both sides, papillae rarely forked , or toothed by projecting cell ends, pitted or nonpitted; proximal cells elongate , often differentiated in alar region, sometimes undifferentiated. Specialized asexual reproduction absent or occasionally present as brood leaves, microphyllous branches, borne in axils of distal leaves or as rhizoidal tubers. Sexual condition autoicous , dioicous or pseudomonoicous. Seta solitary or several per perichaetium , elongate, usually straight, sometimes flexuose or cygneous . Capsule exserted, erect, inclined , or sometimes curved , cylindrical or ovoid , smooth, ridged, furrowed or irregularly wrinkled, sometimes strumose ; stomata present or absent, superficial; annulus present or absent, often compound , deciduous or persistent ; operculum conic or obliquely rostrate from a conic base; peristome single, usually of 16 lanceolate teeth, deeply divided into 2 or rarely 3 divisions, usually vertically striolate or pitted-striolate proximally, papillose distally. Calyptra cucullate , smooth, naked, sometimes fringed at base, usually covering most of capsule, fugacious . Spores mostly spheric, smooth to papillose.

Genera 50-52, species ca. 900 (17 genera, 90 species in the flora ) : worldwide.

Distinctive characters of this large acrocarpous family include the erect, often tomentose stems; mostly narrow, lanceolate, occasionally falcate or falcate-secund leaves, with a single, narrow to broad costa, with or without rhizoids at the base, sometimes ending in a hyaline, occasionally toothed apex, costa in cross section with or without stereid bands , leaf cells usually smooth, sometimes mammillose, or rarely with a single papilla on one or both sides, papillae rarely forked, asexual propagation by specialized deciduous branches, deciduous leaves or leaf apices, rarely rhizoidal tubers; sporophytes usually solitary or rarely clustered, setae mostly elongate, straight or rarely flexuose or cygneous, capsule cylindric to ovoid, erect to horizontal, smooth or ribbed , sometimes strumose, operculum usually obliquely rostrate, peristome single, with 16 teeth often divided 1/2 way to the base, usually striolate or pitted-striolate proximally, papillose distally.[1]

Genus Dicranum

Plants in loose to dense tufts, yellowish green to dark green, dull or shiny. Stems (0.5-) 2-12(-18) cm, erect , simple or forked , densely tomentose with white or reddish brown, smooth to papillose rhizoids, these sometimes nearly absent, rhizoids arising at bases of branches (macronemata) and sometimes in rows scattered along stems (micronemata). Leaves usually lanceolate, rarely ovate , proximal part concave , rarely flat, distal subula keeled to tubulose , erect-appressed, erect-patent or spreading , straight, weakly curled, crispate or cirrate when dry, generally falcate-secund, less often straight, undulate , rugose or smooth; apices acute to obtuse , tips sometimes deciduous, apparently a means of asexual reproduction; margins plane to incurved or involute , entire to serrate in distal part, entire proximally; laminae 1- or 2-stratose at margins or sometimes near costa; laminal cells smooth; costa single, ending before apex to excurrent, smooth or toothed on abaxial surface, sometimes with 2-4 serrated ridges abaxially, 1-2 rows of guide cells, two well-developed stereid bands above and below, sometimes slightly differentiated or absent, extending to apex, or ending before the apex, adaxial and (or) abaxial epidermal layers of cells differentiated or undifferentiated, sometimes only a few cells in both layers enlarged; laminal cell walls weakly to strongly bulging, or bulges absent; leaf cells pitted or nonpitted, smooth or sometimes abaxially, rarely adaxially, mammillose , papillose or toothed by projecting cell ends, walls often thickened; distal and median laminal cells short or long, quadrate , rectangular or irregularly angled , proximal cells rectangular to linear , alar cells inflated , 1- or 2-stratose, rarely more, generally orange to brown, rarely poorly differentiated. Specialized asexual reproduction absent or as clusters of 1-6, deciduous, terete , flagelliform branchlets , borne in axils of distal leaves. Sexual condition dioicous or pseudomonoicous; male plants as large as female plants or dwarfed and epiphytic on stem rhizoids of female plants; perigonial leaves ovate, concave, short-acuminate; perichaetial leaves usually convolute-sheathing, abruptly subulate or rarely interior leaves gradually acuminate. Seta solitary or up to 6 per perichaetium , smooth, elongate , erect, twisted when dry, yellow, brown or reddish. Capsule erect or inclined , cylindric , straight or arcuate , smooth, striate or furrowed when dry, annulus of 1-3 rows of usually large, deciduous or persistent cells, sometimes indistinctly differentiated; operculum long-rostrate, straight or arcuate; peristome single, 16 teeth, split 1/3-1/2 their length into 2, rarely 3, divisions, vertically pitted-striolate proximally, papillose above, reddish brown. Calyptra cucullate , smooth, naked, covering most of capsule, fugacious . Spores 12-30 µm, spherical , finely papillose.

Species ca. 140: North America, Mexico, West Indies, Central America, South America, Europe, Asia, Africa, Australia.[2]

Physical Description

Species Dicranum scoparium

Plants in loose to dense tufts, light to dark green, glossy to sometimes dull . Stems 2-10 cm, tomentose with white to brown rhizoids. Leaves very variable, usually falcate-secund, rarely straight and erect , slightly contorted and crisped when dry, sometimes slightly rugose or undulate , (4-) 5-8.5(-15) × 0.8-1.8 mm, concave proximally, keeled above, lanceolate, apex acute to somewhat obtuse ; margins strongly serrate in the distal 1/3 or rarely slightly serrulate ; laminae 1-stratose; costa percurrent , excurrent, or ending before apex, 1/10-1/5 the width of the leaves at base , usually with 2-4 toothed ridges above on abaxial surface, with a row of guide cells , two thin stereid bands , adaxial epidermal layer of cells not differentiated, the abaxial layer interrupted by several enlarged cells that form part of the abaxial ridge, not extending to the apices; cell walls between lamina cells not bulging; leaf cells smooth ; alar cells 2-stratose, well- differentiated, sometimes extending to costa; proximal laminal cells linear-rectangular, pitted , (25-) 47-100(-132) × (5-) 7-12(-13) µm; distal laminal cells shorter, broad, sinuose, pitted, (11-) 27-43(-53) × (5-) 8-12(-20) µm. Sexual condition pseudomonoicous or dioicous; dwarf males on rhizoids of female plants or male plants as large as females; interior perichaetial leaves abruptly long-acuminate, convolute-sheathing. Seta 2-4 cm, solitary, rarely two per perichaetium , yellowish brown to reddish brown. Capsule 2.5-4 mm, arcuate , inclined to horizontal, smooth to striate when dry, yellowish brown to reddish brown; operculum 2-3.5 mm. Spores 14-24 µm. Capsules mature spring . [source]

Dicranum scoparium is undoubtedly the most polymorphic species of the genus in North America. It is commonly called the broom moss because the leaves are œswept or turned in the same direction . However, the habit of the leaves varies from strongly falcate-secund, i.e. , the swept state, to straight and erect, especially prevalent in northern plants. The leaf shape varies from the typical lanceolate and long-acuminate to the odd ovate-lanceolate and short-acuminate. The leaves are typically smooth, in sharp contrast to the strongly undulate leaves of D. polysetum, but on rare occasion they can be somewhat undulate-rugose. The leaf margins are usually distinctly toothed in the distal 1/3 but at times plants in some populations have extremely weak serrations , appearing nearly entire. The costae vary in extent from subpercurrent to shortly excurrent. The abaxial surface of the costae have two to four toothed ridges, compared to the two in D. polysetum, but in some forms they are almost nonexistent. The distal areolation of the leaves seems to remain constant in the myriad forms of D. scoparium, the cells being short-sinuose with pitted walls, generally containing conspicuous oil-drops. [source]

Plants growing in arctic North America and those in extremely wet habitats , such as bogs , often have a different superficial appearance . The leaves are straight, erect, ovate-lanceolate, short-acuminate with weak serrations on the margins, and the abaxial ridges on the costae are poorly developed. Sometimes the plants have distal shoots with abnormal appearing leaves that are shorter and broader than those below. Some of these collections have been referred to Dicranum latifolium, which I consider to be a synonym of D. scoparium. Further field and laboratory studies are required to clarify the taxonomic status of those plants. In the sterile state, large-leaved plants of D. scoparium can be confused with D. majus. The latter is immediately distinguished by a double row of guide cells, instead of the single row in the former, thicker stereid bands, distal cells that are narrower and more elongate and costae that have small teeth or serrulations distally on the abaxial surface instead of the characteristic 2-4 toothed ridges of D. scoparium. When fruiting, the solitary, rarely paired , sporophytes of D. scoparium distinguish it from D. majus, which has multiple sporophytes, 2-5 per perichaetium. [source]

Habit: Nonvascular

Habitat

Soil, humus , humus over rock, decaying stumps and logs , tree bases in dry to mesic woodlands; sometimes bogs , fens and swamps ; 50-2900 m.

Typically found at an altitude of 0 to 4,701 meters (0 to 15,423 feet).[3]

Taxonomy

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Synonyms

Dicranoloma otii Sakurai • Dicranum angustifolium Kindberg in Macoun • Dicranum canadense Kindberg in Macoun • Dicranum condensatum Hedwig • Dicranum consobrinum Renauld and Cardot • Dicranum dillenii Taylor • Dicranum kindbergii Paris • Dicranum latifolium J. J. Amann • Dicranum mexicanum W. P. Schimper in Bescherelle • Dicranum otii (Sakurai) Sakurai • Dicranum pallidum Bruch and W. P. Schimper Ex C. M�ller • Dicranum rigidifolium Sakurai • Dicranum scopariiforme Kindberg

Notes

Name Status: Accepted Name .

Last scrutiny: 19-Jul-2004

Similar Species

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Members of the genus Dicranum

ZipcodeZoo has pages for 32 species, subspecies, varieties, forms, and cultivars in this genus:

D. acutifolium (Acuteleaf Dicranum Moss) · D. angustum (Dicranum Moss) · D. bergeri (Undulate Dicranum Moss) · D. bonjeanii (Bonjean's Dicranum Moss) · D. brevifolium (Shortleaf Dicranum Moss) · D. condensatum (Condensed Dicranum Moss) · D. elongatum (Elongate Dicranum Moss) · D. flagellare (Dicranum Moss) · D. flavescens (Dicranum Moss) · D. fragilifolium (Fragile Leaf Dicranum Moss) · D. fulvum (Dicranum Moss) · D. fuscescens (Dicranum Moss) · D. fuscescens var. fuscescens (Dicranum Moss) · D. groenlandicum (Greenland Dicranum Moss) · D. howellii (Howell's Dicranum Moss) · D. latifolium (Wideleaf Dicranum Moss) · D. leioneuron (Dicranum Moss) · D. majus (Dicranum Moss) · D. montanum (Montane Dicranum Moss) · D. muehlenbeckii (Muehlenbeck's Dicranum Moss) · D. ontariense (Ontario Dicranum Moss) · D. orthophyllum (Dicranum Moss) · D. pallidisetum (Dicranum Moss) · D. platycaulon (Spotted Jewfish) · D. plurisetum (Poey's Grouper) · D. polysetum (Dicranum Moss) · D. rhabdocarpum (Dicranum Moss) · D. scoparium (Dicranum Moss) · D. spadiceum (Dicranum Moss) · D. spurium (Dicranum Moss) · D. tauricum (Dicranum Moss) · D. viride (Dicranum Moss)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal February 27, 2008:

Identifiers

Footnotes

  1. Robert R. Ireland Jr. "Dicranaceae". in Flora of North America Vol. 27 Page 12, 39, 331, 358, 360, 426, 427, 433, 440, 443, 444, 548, 564. Oxford University Press. Online at EFloras.org. [back]
  2. Robert R. Ireland Jr. "Dicranum". in Flora of North America Vol. 27 Page 9, 10, 26, 32, 33, 38, 359, 360, 362, 386, 397, 398, 405, 406, 411, 420,. Oxford University Press. Online at EFloras.org. [back]
  3. Mean = 282.760 meters (927.690 feet), Standard Deviation = 522.980 based on 50,050 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
Last Revised: 2014-05-14