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Weissia controversa

(Controverial Weissia Moss)

Common Names

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Common Names in English:

Controverial Weissia Moss

Description

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Family Pottiaceae

Plants usually turf-forming or loosely cespitose, green distally and brown proximally. Stems 0.2-4(-10) cm, irregularly branching, mostly rounded-pentagonal but occasionally rounded-triangular in section , hyalodermis usually absent, sclerodermis sometimes present, central strand usually present, radiculose , occasionally bare or tomentose , axillary hairs several cells in length, sometimes the proximal 1-3 cells brownish. Stem leaves usually appressed and often contorted when dry, spreading when wet, ovoid to lanceolate or lingulate , often channeled or keeled , rarely concave , mostly ca. 1.5-3.5 mm; base usually ovate to oblong , occasionally sheathing the stem; margins usually recurved proximally, occasionally plane , incurved , or involute , entire or sometimes dentate distally, occasionally bordered by thick-walled or elongate cells or cells in one or more layers; apex rounded-obtuse to more commonly narrowly acute; costa ending a few cells before the apex to short-excurrent or long-excurrent as an awn , sometimes with photosynthetic outgrowths adaxially, adaxial cells quadrate or elongate in usually 2-4 rows , costa in medial transverse section usually with a differentiated epidermis adaxially or on both sides, 1 or 2 stereid bands , the abaxial stereid band usually rounded or reniform , guide cells in 1(-3) layers, hydroid strand occasionally present (sometimes multiple ) ; basal laminal cells usually differentiated, smooth or lightly papillose , rectangular, generally filling the base medially, sometimes rising marginally in a V shape , occasionally bulging, usually slightly wider than the distal laminal cells; distal laminal cells usually subquadrate , occasionally hexagonal or rarely short-rectangular or rhomboid , mostly small, ca. 9-16 mm wide, 1:1, papillae usually present over the distal laminal cells, solid or occasionally hollow, usually 2-fid but occasionally simple , sometimes flattened or compound , cell walls mostly evenly thickened, superficially flat to bulging, sometimes bulging only adaxially, usually in one layer. Specialized asexual reproduction common, by multicellular (rarely 1-cellular) gemmae borne on stalks in the leaf axils or more seldom on leaves, or by obovoid brood bodies borne on rhizoids in the soil, rarely by reduced or fragile leaves or fragile stems. Sexual condition dioicous or monoicous, occasionally rhizautoicous ; perigonia and perichaetia terminal or occasionally lateral on short branchlets . Perigoniate plants occasionally smaller than the perichaetiate, seldom nearly stemless and budlike. Perichaetial leaves often sheathing in the basal portion and then with elongate-rhomboid cells basally, usually larger than the cauline leaves, long-oval to long-lanceolate. Sporophytes often in transformation series of peristome reduction and seta shortening. Seta usually solitary, elongate, often twisted. Capsule stegocarpous or cleistocarpous , theca ovoid to cylindric , neck usually small or nearly absent; annulus little differentiated or of 1-2 rows of vesiculose cells, occasionally revoluble or deciduous in pieces ; operculum short-conic to short-rostrate, cells in straight or oblique rows; peristome teeth occasionally absent, more usually erect or twisted usually dextrose (counter clockwise ), yellow, orange, or red, rudimentary or consisting of 16 mostly twice cleft , spiculose, striate , or papillose, lanceolate teeth, or 32 linear , usually densely spiculose filiform divisions, the basal membrane usually low or absent, occasionally very high and trabeculate . Calyptra cucullate , smooth, occasionally mitrate, rarely papillose. Spores usually ca. 10-15 µm, occasionally much larger. Laminal KOH color reaction yellow to orange-red or red in 2% KOH solution.

Genera ca. 77, species ca. 1450 (40 genera, 165 species in the flora ) : worldwide, characteristic of harsh habitats .

This is the largest family of the mosses in number of genera. Its taxonomy is commonly considered difficult because of the obscure areolation , small size of the plants , and apparent phenotypic variation . A recent generic-level revision by R. H. Zander (1993) pulled together the scattered literature and de-emphasized sporophytic characters, allowing easier identification of sterile plants. The phylogenetic scheme adopted here approximates that of Zander (1993) as modified by Zander (2006) except that Gymnostomiella and Luisierella are moved from the Barbuloideae to the Pottioideae, in part for convenience in identification. The large number of anatomical characters available permits better identification of previously poorly understood taxa. The color tests refer to the reaction of the cell walls of the distal laminal areolation to 2% potassium hydroxide solution, which may require examination under the compound microscope for determination. Sectioning of leaf and stem is necessary and is described by Zander (1993) . A twisted peristome, strongly differentiated costal anatomy , and the complexly papillose distal laminal cells are characteristic of this mostly acrocarpous family, commonly found in harsh environments.[1]

Genus Weissia

Plants in low cushions or turfs or loosely cespitose, green distally, brown to tan or yellow proximally. Stems to 1 cm, hyalodermis weakly differentiated to distinct , seldom absent, sclerodermis weakly differentiated in 1-2 layers, central strand present; axillary hairs with proximal 1-2 cells somewhat thicker walled. Leaves incurved , commonly tubulose and often contorted or spiraled when dry, spreading when moist; long-ligulate, oblong or triangular to long-lanceolate, 1.5-2.5(-4) mm; adaxial surface broadly channeled across leaf; base scarcely differentiated to ovate or rectangular, occasionally half-sheathing; distal margins usually sharply incurved, occasionally merely erect , seldom plane , entire ; apex sharply acute to subulate , occasionally broadly acute, obtuse , or weakly cucullate ; costa shortly and sharply mucronate , adaxial outgrowths absent, adaxial cells quadrate to short-rectangular except occasionally elongate near apex, in 4-8 rows ; transverse section ovate, occasionally circular or semicircular, adaxial epidermis present, adaxial stereid band present, guide cells 4-6(-8) in 1 layer, hydroid strand absent, abaxial stereid band present, crescent in sectional shape , abaxial epidermis present or occasionally absent; basal cells differentiated across leaf, rarely rising higher along margins in a V shape, rectangular, occasionally rhomboid , 2-5:1; distal medial cells subquadrate to hexagonal, 7-13 µm, papillae 2-fid, 2-6 per lumen , occasionally fused into a large multiplex papilla covering the lumen, occasionally spiculiform and branching. Specialized asexual reproduction rare, as rhizoidal gemmae. Sexual condition monoicous (usually autoicous ), occasionally dioicous; perichaetia terminal , interior leaves occasionally sheathing seta , little different from cauline leaves or somewhat larger. Seta 0.1-1.3 cm. Capsule stegocarpic or cleistocarpic; theca elliptical to short-ovate or cylindric , 1-2.2 mm, annulus in ca. 2 rows of persistent , vesiculose cells or not differentiated; operculum when present conic to rostrate ; peristome teeth 16 or rudimentary or absent, occasionally removed with operculum, oblong-truncate to long-triangular, often irregularly cleft , straight or twisted weakly counterclockwise , mouth occasionally closed by a remnant of the spore sac . Calyptra cucullate. Spores 14-28 µm. KOH laminal color reaction yellow.

Species ca. 97: worldwide except Antarctica; found mostly on soil.

A world evaluation of Weissia and Trichostomum (R. H. Zander 1993) at the generic level suggested that species of the two genera might be shuffled into a more natural arrangement if taxa with identical or nearly identical gametophytes were grouped, with differences in sporophytes easily and simply explained by reduction. It is insufficient, however, to simply split Weissia and Trichostomum into two genera, as was implemented by Zander, based on leaf margins sharply incurved or erect to nearly plane, respectively. Weissia jamaicensis and T. crispulum have similar gametophytes but differ markedly in the leaves of the former being sharply incurved marginally and of the latter nearly plane to merely erect. No major changes were made, however, for this treatment given the need for a full revision . Certain Weissia species with erect leaf margins may have a somewhat cucullate leaf apex similar to that of T. crispulum, but the lamina of the latter is generally broader, 16-20 cells across on one side of the costa just above mid leaf (except in strongly reduced specimens with short-ovate leaves), while Weissia species with which it may be confused have laminae usually 10-15 cells across a lateral lamina. The present species concepts are largely identical with those of A. Stoneburner (1985) with exceptions as noted.

All species of Weissia with sharply inflexed distal leaf margins have a tendency to show adaxially bulging cells in leaf section, possibly because the inflexion crowds the cells. This differential bulging of cell superfices is probably homoplastic to adaxially bulging distal laminal cells in other pottiaceous genera without sharply inflexed distal margins, such as Hyophila. Thus, the close relationship of Weissia with Hyophila and relatives cladistically demonstrated by R. H. Zander (1993) is probably an artifact . Regarding the hymenium that may be seen closing the newly deoperculate capsules of the eperistomate segregate genus Hymenostomum, such a membrane is present in all species of the genus, being the top of the spore sac, and it is simply more evident in the eperistomate species.[2]

Physical Description

Species Weissia controversa

Leaves short- to long-lanceolate, base weakly differentiated to ovate , shoulders weak or absent, distal laminal margins strongly and usually but not always sharply incurved or inrolled , apex plane to channeled , acute, mucro usually weak, of 1-5(-8) cells ; costal adaxial stereid band smaller than the abaxial ; distal laminal cells 6-13 µm wide. Sexual condition monoicous. Seta elongate , 0.3-0.8 cm. Capsule stegocarpic, long-ovate to cylindric , operculum differentiated, falling, peristome present, teeth rudimentary to lanceolate, or occasionally absent. Capsules mature throughout year depending on area of the flora . [source]

This treatment of Weissia controversa follows the study of A. Stoneburner (1985), which justifiably included W. andrewsii, and, agreeing with H. A. Crum and L. E. Anderson (1981), pointed out the great variation in peristome development including occurrence of both eperistomate and peristomate capsules in the same collection . The present treatment includes all flora area reports of W. condensa, a morphologically distinct European species with characters as listed in Excluded Species. Rhizoidal gemmae were reported by W. D. Reese (1988) but these are apparently rare. Weissia viridula Bridel is an illegitimate name that has been much used for this taxon . [source]

Habit: Nonvascular

Habitat

Weedy, soil, rock, disturbed areas, roadsides, fields , acid or calcareous substrates

Typically found at an altitude of 0 to 4,653 meters (0 to 15,266 feet).[3]

Taxonomy

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Ambiguous Synonyms

  1. Dicranoweisia pumecicola Sakurai, 1934
  2. Dicranoweisia riparia (Hampe) Paris, 1896
  3. Dicranum xanthodon Hedwig, 1801
  4. Grimmia crispa A. Roth ex P. G. G�rtner, B. Meyer & Schreber, 1802
  5. Gymnostomum oranicum /i> (C. M�ller) Rehman Ex Paris, 1900
  6. Hymenostomum mexicanum Cardot, 1909
  7. Hymenostomum oranicum /i> (C. M�ller) Paris, 1900
  8. Hymenostomum rutilans (Nees & Hornschuch) Hampe, 1837
  9. Hymenostomum subglobosum Nees & Hornschuch, 1823
  10. Mollia viridula Lindberg, 1879
  11. Rechingerella macedonica J. Fr �hlich, 1963
  12. Simophyllum viridulum Lindberg, 1871
  13. Trichostomum sciophilum C. M�ller, 1898
  14. Weissia andrewsii E. B. Bartram, 1927
  15. Weissia apiculata (Nees & Hornschuch) Rabenhorst, 1848
  16. Weissia brachycarpa C. M�ller, 1899
  17. Weissia brandegei Austin, 1875
  18. Weissia curvicaulis Bridel, 1806
  19. Weissia cyrnaea Bridel, 1827
  20. Weissia flavipes J. D. Hooker & Wilson, 1854
  21. Weissia graeca Schiffner, 1920
  22. Weissia linguaelata J. Shaw, 1878
  23. Weissia longidentata R. S. Williams, 1903
  24. Weissia microstoma Hornschuch Ex Nees & Hornschuch, 1831
  25. Weissia microtheca Th �riot, 1932
  26. Weissia mutabilis Bridel, 1801
  27. Weissia nudiflora C. M�ller & Hampe, 1855
  28. Weissia obscura R�hling, 1812
  29. Weissia oranica C. M�ller, 1899
  30. Weissia rauei Austin, 1878
  31. Weissia rigescens Brotherus, 1899
  32. Weissia riparia Hampe, 1860
  33. Weissia sinensis Th �riot, 1909
  34. Weissia sulcata Th �riot, 1932
  35. Weissia vallis-gratiae C. M�ller, 1899

Unambiguous Synonyms

  1. Gymnostomum rauanum Austin
  2. Mollia viridula (Withering) Lindberg
  3. Weissia andrewsii E. B. Bartram
  4. Weissia brandegeei Austin
  5. Weissia controversa var. australis (Austin) Schornherst
  6. Weissia controversa var. longiseta (Lesquereux & James) H. A. Crum, Steere & L. E. Anderson
  7. Weissia controversa var. wolffii (Lesquereux & James) H. A. Crum, Steere & L. E. Anderson
  8. Weissia curvicaulis Bridel
  9. Weissia longiseta Lesquereux & James
  10. Weissia microodonta Hedwig
  11. Weissia viridula var. nitida Renauld & Cardot
  12. Weissia wolfii Lesquereux & James

Notes

Name Status: Accepted Name . Latest taxonomic scrutiny: 19-Jul-2004

Similar Species

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Members of the genus Weissia

There are approximately 177 species in this genus. Here are just 100 of them:

W. abbreviata · W. acuta · W. alianuda · W. americana · W. andersoniana (Anderson's Weissia Moss) · W. andrewsii · W. apiculata · W. apocaulos · W. argentinica · W. artocosana · W. atra · W. atrovirens · W. austro-crispa · W. ayresii · W. balansae · W. balansaeana · W. bizotii · W. brachycarpa · W. brachypelma · W. brachypoma · W. breutelii · W. breviseta · W. calcarea · W. canaliculata · W. capillacea · W. cataractae · W. chrysea · W. cirrata · W. cirrhata · W. coarctata (African Carp) · W. compacta · W. condensa (Condensed Weissia Moss) · W. condensata · W. contermina · W. controversa (Controverial Weissia Moss) · W. controversa var. australis · W. controversa var. crispata · W. crispa · W. crispata · W. crispula · W. cucullata · W. curvicaulis · W. curvifolia · W. curvirostris · W. cylindrica · W. denticulata · W. dieterlenii · W. diffidentia · W. edentula · W. erythrogona · W. exserta · W. fallax · W. felipponei · W. flavescens · W. flavipes · W. fornicata · W. ganderi · W. ghatensis · W. glauca · W. glazioui · W. groenlandica · W. hedwigii (Hedwig's Weissia Moss) · W. humicola · W. inclinans · W. incurva · W. inoperculata (Weissia Moss) · W. intermedia · W. jamaicensis (Jamaican Weissia Moss) · W. kaikouraensis · W. krassavinii · W. kunzeana · W. lanceolata · W. latifolia · W. latiuscula · W. levieri · W. ligulaefolia (Liguleleaf Weissia Moss) · W. ligulifolia · W. lineaefolia · W. longidens · W. longidentata · W. longifolia · W. longirostris · W. longiseta · W. lorentzii · W. ludoviciana · W. macrocarpa · W. macrospora · W. maritima · W. megalospora · W. micacea · W. microdonta · W. microstoma · W. mittenii · W. mucronata · W. mucronulata · W. muehlenbergiana · W. muhlenbergiana · W. multicapsularis · W. mutabilis · W. neocaledonica

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. Richard H. Zander "Pottiaceae". in Flora of North America Vol. 27 Page 5, 12, 13, 110, 163, 265, 286, 377, 381, 468, 476, 482, 491, 548, 562, 56. Oxford University Press. Online at EFloras.org. [back]
  2. Richard H. Zander "Weissia". in Flora of North America Vol. 27 Page 15, 309, 478, 489, 490, 493, 499, 502, 512, 513, 516, 518, 587. Oxford University Press. Online at EFloras.org. [back]
  3. Mean = 201.110 meters (659.810 feet), Standard Deviation = 350.830 based on 2,374 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
Last Revised: 2009-04-24