England's Rare Mosses and Liverworts: Their History, Ecology, and Conservation

England's Rare Mosses and Liverworts: Their History, Ecology, and Conservation: Their History, Ecology, and Conservation

Ron D. Porley
Series: WILDGuides
Copyright Date: 2013
Pages: 224
https://www.jstor.org/stable/j.ctt2jc908
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    England's Rare Mosses and Liverworts: Their History, Ecology, and Conservation
    Book Description:

    This is the first book to cover England's rare and threatened mosses and liverworts, collectively known as bryophytes. As a group, they are the most ancient land plants and occupy a unique position in the colonization of the Earth by plant life. However, many are at risk from habitat loss, pollution, climate change, and other factors. Britain is one of the world's best bryologically recorded areas, yet its mosses and liverworts are not well known outside a small band of experts. This has meant that conservation action has tended to lag behind that of more charismatic groups such as birds and mammals. Of the 916 different types of bryophyte in England, 87 are on the British Red List and are regarded as threatened under the strict criteria of the International Union for the Conservation of Nature.

    This book aims to raise awareness by providing stunning photographs--many never before published--of each threatened species, as well as up-to-date profiles of 84 of them, including status, distribution, history, and conservation measures. The book looks at what bryophytes are, why they are important and useful, and what makes them rare; it also examines threats, extinctions, ex situ conservation techniques, legislation, and the impact of the 1992 Convention on Biological Diversity.

    Provides the first treatment of England's rare and threatened mosses and liverwortsFeatures stunning photographs--many never before published--of each species and many of their habitatsTreats each species in a handy and attractive double-page layoutIncludes up-to-date profiles of 84 species, including status, distribution, history, and conservation measuresPresents the first overview of English bryophyte conservationOffers invaluable guidance to people working in conservation in England, the British Isles, Europe, and beyond

    eISBN: 978-1-4008-4691-7
    Subjects: Botany & Plant Sciences, British Studies

Table of Contents

  1. Front Matter
    (pp. 1-2)
  2. Table of Contents
    (pp. 3-4)
  3. Introduction
    (pp. 5-7)

    This is a book about mosses and liverworts, collectively known as bryophytes, a term derived from ancient Greek and first used around 1878. Britain is currently home to 1,044 species, comprising 752 mosses and 292 liverworts (1,048 if the four British hornworts are included). They are small, relatively simple plants that live on the land (although some have returned to freshwater), and depend upon water for fertilization. They are the earliest known land plants and were thriving on the ancient landmasses of Pangaea and Gondwana-land millions of years before flowering plants made their entrance onto the world’s evolutionary stage. As...

  4. What are bryophytes and why are they important?
    (pp. 9-13)

    A bryophyte is a land plant with enclosed reproductive structures that does not have highly developed vascular tissues (for the internal transport of water and nutrients). Neither does the plant have a flower or produce seeds, reproducing as it does sexually via spores and/or asexually by a range of propagules. Such a definition scarcely does justice to the beauty of these small humble plants that adorn our world. The exquisite lithographic prints by Ernst Haeckel (1904), illustrating the remarkable diversity of form of mosses (left) and liverworts speaks to us much more lucidly than words can. Although the term ‘bryophyte’...

  5. Rarity in bryophytes
    (pp. 13-19)

    The pressure of a steadily increasing human population on the biodiversity of the planet is an all too familiar theme, bringing with it habitat loss and fragmentation, modification (including the spread of invasive species), over exploitation, pollution and climate change. Closer to home the natural environment in England is much less rich now than 50 years ago (NE, 2008). The global, regional and local decline in rare (and common) bryophytes can, in part, be attributed to these factors.

    But what is a rare bryophyte? In practice this a difficult question to answer. The first thing to recognize is that of...

  6. Conservation measures
    (pp. 19-26)

    Today ‘conservation’ is a well-worn term and is used in many contexts. Protection guardianship, restoration, preservation and management are just a few of the words used to define it. This section aims to show how nature conservation is delivered in the wider sense and howbryophyteconservation impacts on the bryophyte flora of England. Conservation needs to operate at a number of complementary levels if it is to be effective. The two foremost measures to protect bryophytes in England are through habitat conservation (including habitat management, restoration or enhancement) and species conservation implemented through Action Plans or similar. Other valuable...

  7. People and bryophyte conservation
    (pp. 26-31)

    The conservation of England’s bryophytes could not happen without the involvement of many people at all levels and in many disciplines, from statutory conservation agencies to Non Governmental Organisations (NGOs), Government departments, universities and research institutions, specialist plant societies and last, but not least, the individual. There must be cooperation and a free flow of information between all the players if the threats to the English bryophyte flora are to be managed and minimized. Similarly, it is vital that the scientists who describe new species, or split or lump existing ones or tinker with the names, ensure that this information...

  8. The Red List
    (pp. 31-34)

    It is generally acknowledged that Britain is one of the most bryologically well-worked regions in the world (Crundwell, 1992; Cleavitt, 2005). A combination of the high quality distributional data, together with population data for some species, enables pragmatic assessments of the conservation status of bryophytes in Britain.

    New bryophytes are added to the British list by an active group of recorders on an annual basis. England is no exception and within the last decade (2000–2010) at least ten new species have been added to the list. Some, such asSeligeria campylopoda, were added to the English (and British) list...

  9. Overview of threatened English bryophytes
    (pp. 34-43)

    The English bryophyte flora currently totals 922 species, comprising 252 liverworts, 666 mosses and 4 hornworts. In all, 87 English species occur on the revised British Red List (Hodgetts, 2011), of which 24 are liverworts and 63 are mosses. About 9% of England’s bryophyte flora is therefore at risk of extinction. Of the Red Listed species, 61 are also BAP priority species and 19 are fully protected under Section 13 of the Wildlife and Countryside Act 1981. Some 30 species (seepage 203) have no post-1980 records and are considered to be lost from England (source Hill, Blackstock, Long & Rothero,...

  10. THE SPECIES PROFILES
    • [Introduction]
      (pp. 44-45)

      This section presents species profiles accompanied by photographs of 84 of the 87 threatened bryophytes on the revised British Red List (Hodgetts, 2011) that occur in England. If a photograph was not taken in England this is indicated. Three bryophytes on the Red List (Bartramia stricta, Bryum cyclophyllum and Scapania praetervisa) have not been recorded in England for more than 50 years and are therefore excluded from the profiles (seepage 206).

      Both common and scientific names are given (see alsoAppendix 2). English names for bryophytes follow Edwards (2012) and the nomenclature for scientific names follows Hill, Blackstock, Long &...

    • Acaulon mediterraneum Spiny-spored Pygmy-moss
      (pp. 46-47)

      This is an exceedingly minute moss, only 1∙5 mm or less tall forming scattered turfs. The genusAcaulon, meaning ‘without a stem’, comprises some of the smallest mosses in Britain. The leaves are broadly oval with a nerve that ends in, or slightly extends beyond, the obscurely toothed apex and is bent slightly backwards. It is monoicous and sporophytes are common but are hidden by the concave, overlapping leaves that give the plant a bud-like appearance. Microscopic examination of spores is necessary to separate it from its congenerA. muticum; spores ofA. mediterraneumhave long spines. Asexual propagules are...

    • Acaulon triquetrum Triangular Pygmy-moss
      (pp. 47-49)

      This species is one of England’s smallest mosses, forming reddish or golden-brown scattered turfs of shoots to 1∙5 mm or less. The leaves are strongly keeled with a bent back leaf tip giving it a distinctive triangular form (hencetriquetrum). It is monoicous and sporophytes are common with the capsule held to one side on a short curved seta. Asexual propagules are absent. It shows an annual shuttle life-history strategy, with high reproductive effort invested in producing relatively few large spores.

      It grows on bare, usually calcareous, soils close to the sea with a preference for south-facing slopes and on...

    • Andreaea frigida Icy Rock-moss
      (pp. 49-51)

      Andreaea, named after Johann Andreae, a German pharmacist (1724–1793), is a distinctive group of mosses that form small blackish to reddish cushions on rocks in the hills and mountains. The tiny capsule separatesAndreaeafrom all other mosses; it opens by four longitudinal slits or valves, which remain attached at the top, and has given the group the alterative name of lantern mosses.A. frigidais relatively robust for anAndreaea, with shoots over 4 cm tall and forming cushions several centimetres across that can coalesce into extensive patches. It is monoicous and sporophytes are commonly produced during the...

    • Anomodon attenuatus Slender Tail-moss
      (pp. 51-52)

      Anomodon attenuatusis a slender pleurocarpous moss that forms olive-green to golden-brown rough mats with primary creeping stems to 3 cm long. From these arise numerous irregular curved secondary stems, which sometimes narrow to form a flagelliform (whip-like) drooping branch with progressively smaller leaves (hence the epithetattenuatus). The small (less than 2 mm long) nerved leaves are broadly oval below, tapering to a blunt, weakly toothed apex, and have a matt surface due to a covering of 2–3 papillae (wart-like protuberances) on each leaf cell. When dry the leaves are closely appressed to the stem and overlap, but...

    • Anomodon longifolius Long-leaved Tail-moss
      (pp. 52-54)

      The species forms yellowish-green rough mats with shoots to 2 cm long. It is a more slender plant thanA. attenuatus (page 51), and in fact shows a closer resemblance to other common mosses such asAmblystegium serpensandHeterocladium heteropterum. Key features are the nerved leaves which taper from a broad base to a fine point, and the very fine secondary branches that occasionally form a flagelliform (whip-like) drooping branch with progressively smaller leaves. In the dry state the leaves are appressed to the stem but spread out when moistened. It is dioicous and sporophytes are unknown in Britain....

    • Aplodon wormskioldii Carrion-moss
      (pp. 54-56)

      This moss forms loose bright green tufts, sometimes extensive, to 5 cm tall. It has broad soft leaves with entire margins, a nerve that ends below the apex and often a bent back tip. It is monoicous and sporophytes are frequent. It is the sporophyte that provides the best field character, having a thin, rather weak, translucent seta and an erect capsule with a conspicuous neck. Asexual propagules are absent. As in other members of the Splachnales, its spores, which are sticky and adhere to each other, are dispersed by flies. It behaves as a short-lived shuttle species.

      Known as...

    • Atrichum angustatum Lesser Smoothcap
      (pp. 56-57)

      This species forms turfs of olive-green sometimes reddish-tinged shoots to about 2 cm tall, rarely more. The genus, once known asCatharinea, named under royal patronage for Catherine II of Russia (1729–1796), is recognized by longitudinal lamellae on the upper side of the nerve, a character shared by other members of the Polytrichales. The leaves, which are straight or sometimes faintly undulate when moist but curled and crisped when dry, taper from a narrow base and are distinctly toothed on the upper margins. It is easily confused with the commonA. undulatumand its identity should be confirmed microscopically....

    • Bruchia vogesiaca Vosges Candle-moss
      (pp. 58-59)

      This minute moss, the specific epithet referring to its original collection from the Vosges Mountains in France, forms scattered turfs or solitary shoots to 3 mm tall (including capsules, up to 7 mm). The leaves are expanded at the base and taper gradually to a long thin leaf tip composed largely of an excurrent nerve. It is monoicous and sporophytes are common, often providing the only clue to the presence of this easily overlooked moss, and show the distinctive swollen neck region characteristic of the genus. Filamentous gemmae on a persistent protonema have been reported from Portugal (Sérgio, Jansen & Séneca,...

    • Bryum calophyllum Blunt Bryum
      (pp. 60-61)

      This is a small, pale, olive-green to pinkish turf-forming moss with shoots to 15 mm tall. The namecalophyllumis derived from the Greek meaning ‘beautiful leaves’ and refers to the delicately coloured, ovate concave leaves with a blunt or shortly pointed apex, a feature that sets this species apart from most other members of this taxonomically difficult genus (but seeB. marratii, page 65). It is monoicous with nodding capsules held on straight setae. Specialized asexual propagules are unknown. It behaves as a short-lived shuttle, with high investment in sexual reproduction and production of large spores (26–42 μm),...

    • Bryum gemmiparum Welsh Thread-moss
      (pp. 61-63)

      This is a moderately sized dull to olive-green turf-forming moss, reddish in the lower parts, with densely packed shoots to 3 cm tall. The leaves are held close to the stem when dry, but spread widely when moist. They are oval and distinctly concave, with a thick nerve that ends in the leaf apex. It is dioicous and sporophytes are unknown in Britain. It has specialized asexual propagules in the form of green to reddish bulbils clustered amongst the upper leaves, and orange to pinkish spherical tubers are sometimes present on short rhizoids. It is said to be a colonist,...

    • Bryum knowltonii Knowlton’s Thread-moss
      (pp. 63-65)

      This species, named in honour of T. Knowlton (1692–1782), botanist and gardener to the Earl of Burlington, is a small pale green to reddish turf-forming moss with shoots to 10 mm tall. Its oval, slightly concave leaves have a reddish base with a nerve that runs into the pointed leaf apex. It is monoicous and sporophytes are common. The naming of manyBryumcan be difficult and mature capsules are necessary for the unambiguous identification ofB. knowltonii. Specialized asexual propagules are unknown in nature although filamentous protonemal gemmae have been produced in culture. This moss behaves as a...

    • Bryum marratii Baltic Bryum
      (pp. 65-67)

      This species, named after its discoverer the mineralogist, conchologist and bryologist F. P. Marrat (1820–1904), is a small bright green turf-forming moss with shoots 2–10 mm tall. The strongly concave oval leaves, with no tinge of red at the base, are blunt tipped. It is monoicous but capsules are not common. The shape of the capsule (short with a pronounced pointed lid) is the best character to separate it fromB. calophyllum(page 60). Specialized asexual propagules are unknown in the wild or in culture, a factor which may in part account for its rarity (Duckettet al.,...

    • Bryum salinum Saltmarsh Thread-moss
      (pp. 67-68)

      This plant is a small yellowish-green turf-forming moss with shoots to 15 mm tall. The leaves, reddish at the base with recurved margins, are narrowly oval and abruptly taper to a point from which a strong nerve extends. The upper leaves are closely packed forming a conspicuous tuft at the shoot tip. It is monoicous and the narrow pear-shaped nodding capsule has a distinctive reddish mouth; certain identification requires examination of the peristome teeth of ripe capsules. The species is very closely related to the widespreadB.archangelicumand intermediate plants are known; the precise taxonomic status ofB. salinumneeds...

    • Cephaloziella baumgartneri Chalk Threadwort
      (pp. 69-70)

      This species, named in honour of the Austrian bryologist Julius Baumgartner (1870–1955), is a minute blackish-green leafy liverwort with bi-lobed leaves, with shoots to 7 mm long and less than 0∙5 mm wide. When present as solitary creeping shoots it can be hard to spot, but it often forms thread-like mats. Its identity must be confirmed microscopically, but it is the only British member of the genus confined to calcareous substrates and it never has any reddish pigmentation.C. baumgartneriis monoicous and sporophytes are fairly frequent. It produces asexual propagules in the form of tiny smooth ovoid gemmae...

    • Cephaloziella dentata Toothed Threadwort
      (pp. 70-72)

      This species is a tiny leafy liverwort, varying from yellowish-green through to reddish-brown, forming solitary creeping shoots up to 8 mm long and about 0∙6 mm wide. The specific epithet refers to the toothed (dentate) leaf lobes, a feature nevertheless shared by a number of other species includingC. massalongi(page 74) andC. nicholsonii (page 75). This species is dioicous, and male inflorescences and sporophytes are unknown in Britain. Specialized asexual propagules are commonly produced on the leaf margins and shoot tips; these gemmae are diagnostic in being heavily invested with wart like projections. It behaves as a colonist....

    • Cephaloziella integerrima Lobed Threadwort
      (pp. 72-73)

      This leafy liverwort is exceedingly small, even by the standards ofCephaloziella, with leafy shoots up to 4 mm long and 0∙5 mm wide. It can form thin, smooth mats but more commonly it is found as solitary creeping shoots, thus is easily overlooked. The margins of the leaf lobes lack teeth, contrasting withC. massalongi (page 74)andC. nicholsonii (page 75). It is monoicous, although sporophytes are rare. Specialized asexual propagules are commonly present in the form of multi-angular gemmae on the margins of the upper leaf lobes. It behaves as a colonist.

      All recent records are from...

    • Cephaloziella massalongi Lesser Copperwort
      (pp. 74-75)

      This species, named after the Italian bryologist C. Massalongo (1852–1928), is a tiny leafy liverwort forming a smooth mat or solitary creeping shoots, very similar to the closely relatedC. nicholsonii (page 75)in having toothed leaf lobes, but generally even smaller in all its parts. Individual shoots are up to 7 mm long and less than 0∙5 mm wide, but under optimal conditions can form dense patches. Microscopic examination is necessary for reliable identification, particularly of plants growing in that which can be hard to name. It is very rarely fertile in Britain, and is presumed to be...

    • Cephaloziella nicholsonii Greater Copperwort
      (pp. 75-77)

      This species, named in honour of the eminent Sussex bryologist W. E. Nicholson (1866–1945), forms smooth mats or scattered creeping shoots about 10 mm long and 0∙5 mm wide. The colour varies, typically greenish but sometimes with purplish-red tints. The combination of toothed leaves, smooth asymmetrical gemmae on the upper leaf margins, and the habitat, may point to this species. It often grows with the Red ListedC. massalongi (page 74)and whilst well-grownC. nicholsoniiis normally larger than the former (apparent in mixed populations), microscopic confirmation is required. It is monoicous but sporophytes are unknown. It behaves...

    • Ceratodon conicus Scarce Redshank
      (pp. 77-79)

      This species, barely 10 mm tall, forms yellowish-green turfs or inconspicuous scattered shoots. It has tiny triangular tapering leaves with entire margins and a nerve that extends beyond the leaf tip. It is dioicous and sporophytes are rare. There is no swelling (struma) at the junction of the erect capsule and seta (unlikeC. purpureus, which does have a struma). Its separation fromC. purpureusis difficult; mature capsules are necessary so that the peristome can be examined microscopically. Specialized asexual structures are unknown and it shows a colonist life-history strategy.

      A strict calcicole, it grows on dry bare sandy...

    • Cheilothela chloropus Rabbit Moss
      (pp. 79-81)

      Cheilothela, meaning ‘thick nipple’, a reference to the thickened beak on the capsule lid, is a dull yellowish to brownish-green turf-forming acrocarp up to 10 mm tall. The leaves have plane margins and taper from a narrow base to a sharp apex giving the shoots a spiky appearance when moist, and held close to the stem when dry; they are more than one cell thick which gives them an opaqueness and rigidity. The dullish appearance is due to numerous rounded protuberances (mammillae) on both upper and lower surfaces. It is dioicous and sporophytes are unknown in Britain and are rare...

    • Cinclidotus riparius Fountain Lattice-moss
      (pp. 81-83)

      Cinclidotus, from the Greek ‘lattice-like’, referring to the peristome around the capsule mouth, is a dark green to blackish compact aquatic plant attached to the substrate, with shoots to 5 cm long. Leaves have thickened margins and a strong nerve extending to the rather blunt apex, are slightly twisted when dry and spreading when moist. It is very similar to, and often grows withC. fontinaloides, but that species is typically more straggling with narrower, more sharply pointed leaves; microscopic examination of transverse sections of leaves is, however, necessary for certain identification. The species is dioicous, only female plants are...

    • Cyclodictyon laetevirens Bright Green Cave-moss
      (pp. 83-85)

      This moss, the only European member of a largely tropical genus, is a bright green (hence ‘laetevirens’) creeping pleurocarp forming rough mats with regularly branched shoots to 8 cm long, often much less. The oval leaves have visibly large cells, a double nerve and a border of long narrow cells running into a short sharp point; they are arranged in one plane giving a flattened appearance to the shoot. It is monoicous and sporophytes are uncommon. Asexual propagules are absent and it behaves as a perennial stayer.

      In England, the plant grows in the half-light of a humid sea cave,...

    • Cynodontium polycarpon Many-fruited Dog-tooth
      (pp. 85-86)

      This is a green cushion-forming moss of variable size, but usually no more than 4 cm tall.Cynodontium(from the Greek) refers to the supposed resemblance in the closely relatedC. bruntoniiof the peristome to a dog’s tooth (ironically this species has now been transferred to another genus,Oreoweisia). The long, narrow gradually tapering leaves are contorted when dry and when moist become erect to spreading; they have recurved margins to above half-way and are toothed at the apex. It is monoicous and the capsules, which are freely produced, are straight with longitudinal furrows. Specialized asexual propagules are unknown...

    • Dialytrichia saxicola Brittle Lattice-moss
      (pp. 87-88)

      Formerly known asDialytrichia fragilifolia, this moss forms small, light to dark green (sometimes grey from silt), compact tufts or loose cushions up to about 10 mm tall. The strongly nerved leaves are parallel sided with a rounded apex that terminates in a small point and the upper leaf margins are crenulated (scalloped). When dry the leaves are loosely twisted around the stem but spread when moist. The fragile nature of the leaves provides a good field character; sometimes only the nerve remains after the leaf lamina has broken away giving a bristly appearance to the cushions. Confusion with fragile...

    • Dicranum spurium Rusty Fork-moss
      (pp. 88-90)

      This acrocarpous moss varies in size, forming golden-green tufts 5 cm or more tall, sometimes less, or scattered shoots. It has relatively broad leaves that taper to a fine tip, which when dry are crisped and wavy and the upper leaves are tufted. When moist the leaves point away from the stem, and superficially resembles some forms of the commonD. scoparium. The moss is dioicous and sporophytes are very rare. Fragile shoot tips are thought to aid local dispersal and it is a perennial stayer, investing little effort into sexual reproduction.

      A plant of lowland heathland, it is particularly...

    • Dicranum undulatum Waved Fork-moss
      (pp. 90-92)

      This species, formerly known asD. bergeri, is a moderately robust yellowish or light olive-green moss with shoots to 15 cm tall. although often much less. Shoots are typically tightly packed together so forming dense tufts or sometimes large hummocks. The narrow tapering leaves, ending in a blunt point, are erect when moist and little altered when dry and are transversely wrinkled (hence the specific nameundulatum). OtherDicranumspecies, particularlyD. bonjeanii, have obviously wrinkled leaves so care is needed in identification. The moss is dioicous and sporophytes are rare. Asexual propagules are unknown and it behaves as a...

    • Didymodon cordatus Cordate Beard-moss
      (pp. 93-94)

      This moss is a small dark green or brownish-green acrocarp with rigid shoots 5–10 mm tall. It forms dense turfs or scattered shoots, often partially buried by soil and overgrown with crustose lichen. When dry the broadly triangular, incurved, slightly concave leaves embrace the stem, but when moist they spread widely. It is dioicous and only female plants are known in Britain. It produces tiny spherical gemmae in the axils of the upper leaves and behaves as a pioneer, with a reliance on asexual propagules for population continuance.

      A coastal plant, it grows on thin sandy soil over Greensand...

    • Didymodon glaucus Glaucous Beard-moss
      (pp. 94-96)

      This species is a small greyish-green (henceglaucus) turf-forming moss up to 3 mm tall. The narrow tapering leaves are curled when dry and spread when moist. It is dioicous and sporophytes are unknown throughout its range; only female plants have been found in Britain. Specialized asexual propagules are present on modified rhizoids in the upper leaf axils, appearing as heavily pigmented chains (moniliform) of up to eight rounded gemmae. Protonematal gemmae (of similar morphology to the axillary gemmae) are also present in culture and nature. It behaves as a colonist, with a moderately long lifespan, low growth rate and...

    • Ditrichum cornubicum Cornish Path-moss
      (pp. 96-98)

      This is a very tiny moss, forming dull-green loose tufts or scattered shoots 1–5 mm tall. The blunt-tipped leaves, which are more crowded towards the shoot apex, are held tightly against the fragile stem when dry and spread when moist. It is dioicous but only male plants have been found in Britain and sporophytes are unknown. Asexual propagules are present in the form of spherical multicellular rhizoidal tubers and these often develop on rhizoids in the lower leaf axils. Chains of filamentous ‘brood cells’ also occur on the protonemata and protonematal gemmae are produced in culture. The species can...

    • Ditrichum subulatum Awl-leaved Ditrichum
      (pp. 99-100)

      This species is a soft, slender, yellow-green turf-forming moss with erect shoots to 8 mm tall. The silky leaves are very narrow, tapering to a long fine point or subula (hence ‘subulatum’) filled largely by an excurrent nerve; the uppermost leaves tend to curve to one side and are wavy when dry. It is monoicous and sporophytes are common. Specialized asexual propagules (tubers) are present on the rhizoids in the form of a spirally twisted row of cells. It behaves as a colonist.

      It is a coastal plant on loose, crumbly, acid sandy, clayey or loamy soils, often on steep...

    • Dumortiera hirsuta Dumortier’s Liverwort
      (pp. 100-102)

      This dark green, semi-translucent, thalloid liverwort, named in honour of the Belgian bryologist and politician B. C. J. Dumortier (1797–1878), is up to 12 cm long and 2 cm wide. The thalli are often forked and it can form extensive hanging mats. It differs from all other Marchantiales in its upper surface appearing to lack any pores or network of lines and in having scattered hairs (hencehirsuta) that are particularly evident on the thalli margins. It can form monoicous or dioicous populations, with male plants more commonly recorded than females. The lobed receptacle of the female plant is...

    • Ephemerum cohaerens Clustered Earth-moss
      (pp. 103-104)

      This minute moss arises from a green persistent protonema, with scattered leafy shoots barely more than 1 mm tall. The narrow leaves have a nerve that extends into the finely pointed apex and the upper margin is toothed (microscopic examination is necessary to separate it from similar species). It is monoicous and the almost spherical sessile capsules are nestled amongst the upper leaves. Specialized asexual propagules are present in the form of large lipid-rich tubers and short-distance dispersal may occur by protonemal fragmentation. Sexual reproductive effort is high, rapidly producing an extensive protonemal mat followed by leafy shoots and sporophytes...

    • Eurhynchiastrum pulchellum Elegant Feather-moss
      (pp. 104-106)

      This is a petite pleurocarp (pulchellummeans small and beautiful) forming green or yellowish-green rough mats with many blunt-tipped short branches arising from the creeping primary stem. Stem and branch leaves differ in size and shape; the former are larger, more or less triangular and taper to a point, whilst the smaller branch leaves are often rounded at the tip. The leaves, which are lightly pleated lengthwise, have a nerve that ends well below the apex and a margin that is finely toothed. The variability in form has caused much confusion until M. O. Hill resolved the situation by demonstrating...

    • Fissidens curvatus Portuguese Pocket-moss
      (pp. 106-107)

      Fissidens(meaning ‘split tooth’, alluding to the peristome teeth surrounding the capsule mouth) are unique amongst mosses in that each leaf has a ‘pocket’ on its forward edge (the vaginant lamina), which the leaf immediately above it neatly slots into, creating shoots that resemble miniature ferns. Formerly known asF. algarvicus, it was initially described by the German botanist H. Solms-Laubach (1842–1915) under this name from material collected at Silves in the Algarve in 1866 (hence the common name), but it was later shown to be synonymous withF. curvatusfrom the Cape, South Africa, collected in 1827 by...

    • Fissidens serrulatus Large Atlantic Pocket-moss
      (pp. 107-109)

      Fissidens serrulatus(for an explanation of the generic name. seeF. curvatus opposite) is one of the larger species with the genus, with green turf-forming closely packed shoots up to 7·5 cm long and 7 mm wide. The numerous non-bordered leaves, arranged in two flat neat rows on opposite sides of the stem, taper abruptly to the leaf tip which is distinctly toothed (henceserrulatus). The diagnostic feature is the occurrence of tiny conical protruberances (mamillae) on the cells which, in the field, imparts a characteristic lustre to the leaves. It is dioicous and only male plants are known in...

    • Grimmia anodon Toothless Grimmia
      (pp. 109-111)

      The genusGrimmia, named after the German bryologist J. F. K. Grimm (1737–1821), is a group of mosses forming cushions or patches on rock from the lowlands to the highest mountains. This species is a small, dark green moss that forms dense cushions with individual shoots to 15 mm tall but often shorter. Although quite variable, the narrow tapering leaves end in silvery hairpoints giving the cushions a greyish appearance when dry. It is monoicous and sporophytes, partially immersed in the upper leaves, are common. The capsule is attached off-centre on a short ‘S’-shaped (sigmoid) seta and it lacks...

    • Grimmia elongata Brown Grimmia
      (pp. 111-113)

      This species is a dull green to reddish-brown moss giving it a rather different appearance to other members of the genus (for derivation of the generic name, seeG. anodon page 109). Shoots reach up to 20 mm tall, giving rise to small cushions or larger patches. The narrow tapering leaves are held close to the stem and are slightly twisted when dry, spreading when moist, with an inconspicuous silver hair-point. It is dioicous and sporophytes are unknown in Britain. Specialized asexual propagules are absent and it behaves as a colonist.

      It is primarily a moss of acid, normally sunny...

    • Homomallium incurvatum Incurved Feather-moss
      (pp. 113-115)

      This moss is a slender, green or light green mat-forming pleurocarp, with creeping shoots reaching 1–2 cm long and closely attached to the substrate. The leaves, about 1 mm long, taper from about mid-leaf to a narrow tip and are characteristically curved upwards and away from the substrate. It is monoicous and sporophytes are common; the capsule is distinctly curved (henceincurvatum) providing another field clue to its identity. Asexual propagules are unknown. The plant can be confused withHypnum resupinatum, but this moss has erect or only slightly curved capsules, although identification should be confirmed microscopically. The plant...

    • Jamesoniella undulifolia Marsh Flapwort
      (pp. 115-117)

      This species is a bright green to reddish-brown leafy liverwort forming smooth mats with shoots to 5 cm long and 3·5 mm wide. The leaves are round with slightly wavy margins and are distant on the lower stem becoming more crowded above. It is dioicous, and although male and female plants are fairly frequent, sporophytes are very rare and do not reach maturity in Britain. Specialized asexual propagules are unknown. It is very similar toOdontoschisma sphagni, which occurs in the same habitat, but that species normally has colourless flagella (thread-like appendages) on the underside of the stem.Jamesoniellawas...

    • Leiocolea rutheana Norfolk Flapwort
      (pp. 117-119)

      This olive-green, strongly aromatic, leafy liverwort forms smooth mats with unbranched shoots up to about 6 cm long and up to 5 mm wide. It has two ranks of overlapping, shallowly bi-lobed leaves with a margin that continues down the stem (decurrent), and a row of tiny but well-developed ciliate ‘underleaves’ on the underside of the stem. It is monoicous and sporophytes are occasional. Specialized asexual propagules are unknown and it behaves as a perennial stayer. Paton (1995) established that two varieties can be recognized in the British Isles, var.laxa(southern England only) and var.rutheana(England, Scotland and...

    • Lejeunea mandonii Atlantic Pouncewort
      (pp. 119-121)

      Lejeuneais a genus of small leafy liverworts named after the French physician and botanist A. L. S. Lejeune (1779–1858). They can be tricky to identify andL. mandoniiis no exception. It forms pale to bright yellow-green smooth mats with shoots barely 1 cm long and about 0·5 mm wide. Its small size is a useful field character, as too is the shape of its leaves, which are rather narrowly rounded at their apex compared to otherLejeuneaspecies. The smooth, round perianths are diagnostic but are difficult to detect in the field. It is monoicous and perianths...

    • Liochlaena lanceolata Long-leaved Flapwort
      (pp. 121-123)

      Formerly known asJungermannia leiantha, this is a small yellowish-green or reddish-brown prostrate leafy liverwort with shoots 10−25 mm long and up to about 3 mm wide. It has shortly oval to oblong leaves with a bluntly rounded apex, these being arranged on either side of the creeping stem, each leaf overlapped by the one behind. The defining character is the smooth cylindrical or club-shaped perianth that is abruptly flattened at its top with a short protuberance in the centre of a shallow circular depression. Fortunately this key feature is usually present as the species is monoicous and perianths and...

    • Lophozia capitata Large-celled Flapwort
      (pp. 123-125)

      This is a yellow-green, occasionally reddish-purple, creeping leafy liverwort with flattened shoots up to 20 mm long and 2 mm wide, often with ascending attenuate shoots tipped with a cluster of smooth green to purplish unicellular gemmae. The bi-lobed leaves are obliquely and alternately inserted on the succulent brittle stem. A combination of absent or rudimentary underleaves, large leaf cells (hence common name) and smooth gemmae separate this from related species. It is dioicous, and whilst male and female plants with perianths are not uncommon, sporophytes are rare. Asexual propagules in the form of gemmae enable the plant to rapidly...

    • Lophozia herzogiana Herzog’s Notchwort
      (pp. 125-126)

      This plant is named after the great German bryologist and biogeographer T. Herzog (1880−1961). It is a small, green, leafy liverwort forming smooth mats with creeping shoots about 10 mm long and up to 1·8 mm wide. It has widely spaced to slightly overlapping bi-lobed leaves, each lobe triangular in shape, and tiny ‘underleaves’ on the underside of the stem. The characteristic field feature is the slender, erect shoot tips with reduced leaves terminating in conspicuous clusters of green gemmae (specialized asexual propagules). It is dioicous, and male and female plants and sporophytes are unknown in Britain. Its life-history is...

    • Marsupella profunda Western Rustwort
      (pp. 127-129)

      This plant is a small purplish-brown leafy liverwort in dense or loose turfs. Individual stems are about 5 mm long and less than 1 mm wide, buten masseform large patches. The tiny, weakly concave leaves are bi-lobed but it is the shape of the lobes that suggestM. profundaand separate it from similar species such asM. sprucei. InM. profundathe leaf lobes are rounded, sometimes broadly ovate or tongue-shaped (acute inM. sprucei). It is monoicous and sporophytes are common. Asexual propagules are lacking and it behaves as a colonist.

      It grows on damp clay...

    • Micromitrium tenerum Millimetre Moss
      (pp. 129-131)

      This species, Britain’s smallest moss, is scarcely 1 mm tall. The leafy shoots develop on persistent protonemata, the juvenile filamentous stage of a moss. The leaves are nerveless, entire or very slightly toothed near the apex and partially conceal a tiny sessile spherical capsule. The capsule is topped by a barely perceptible minute point and an even smaller calyptra or cap, hardly visible to the naked eye, sits atop the immature capsule (hence its name:micro= small,mitrium= a cap). It is monoicous, and sporophytes are frequent. It displays an episodic life-history strategy (During, 1997), adapted to niches...

    • Mielichhoferia elongata Elongate Copper-moss
      (pp. 131-133)

      This species, named in honour of the Austrian bryologist M. Mielichhofer (1772−1847) who discovered the genus in the Austrian Alps, is a distinctive pale green to glaucous moss forming dense velvety turfs with shoots to 15 mm tall. The oval, slightly glossy, overlapping leaves have a thick nerve ending below the finely toothed acute leaf tip. It is dioicous and sporophytes have never been found in England. Deciduous shoots serve as asexual propagules and it behaves as a stress tolerant perennial. In the past it has been treated as a synonym or variety ofM. mielichhoferiana, but molecular work has...

    • Nardia insecta Bug Flapwort
      (pp. 133-135)

      This is a small, yellowish-green or pale to greyish-green, leafy liverwort with creeping shoots about 10 mm long to 1·5 mm wide. It forms thin mats with the tips of individual shoots ascending and when fresh appears slightly fleshy and brittle. The broadly rounded overlapping leaves are arranged in two rows along the stem and are consistently bi-lobed to about one third of the leaf, each lobe roughly triangular in shape. It has tiny but distinct ‘underleaves’ on the underside of the stem. It superficially resembles several other leafy liverworts so microscopic examination is required. It is monoicous and usually...

    • Orthodontium gracile Slender Thread-moss
      (pp. 135-137)

      This is a yellow-green, slender-leaved moss forming turfs or scattered shoots usually less than 10 mm tall. In moist conditions the narrow leaves point in one direction (secund) but when dry are characteristically wispy. It is monoicous and sporophytes are common. The capsule is a pale tan colour and is smooth when dry and empty. It grows with the superficially similar alienO. linearebut that species tends to have slightly stiffer, wider leaves and the mature capsule is reddish-brown and usually ribbed when dry. Specialized asexual propagules are present in the form of protonemal gemmae and it behaves as...

    • Orthotrichum pallens Pale Bristle-moss
      (pp. 137-139)

      This small, dark green moss forms cushions 5–10 mm tall. The leaves, hardly altered when dry, have recurved margins and a nerve that ends just below the blunt leaf apex. It is monoicous and sporophytes are common. The pale (hencepallens) shiny ribbed calyptra (the cap atop the capsule) has an orange tip that provides a good field character in early summer.Orthotrichummeans ‘straight hair’ and refers to the erect sparse hairs on the calyptra, but in some species, includingO. pallens, hairs are absent. Specialized asexual propagules are unknown in Britain. It behaves as a pioneer colonist....

    • Orthotrichum pumilum Dwarf Bristle-moss
      (pp. 139-141)

      This is a small (pumilum= dwarf), pale green moss forming compact cushions to about 5 mm tall. The leaves, little altered when dry, have recurved leaf margins and a nerve that ends just below the rather pointed leaf apex. It is monoicous and sporophytes are common. It shares with the Red ListedO. pallens(page 137) a hairless calyptra but unlike that speciesO. pumilumhas a smooth calyptra rather than a ribbed one. Specialized asexual propagules in the form of protonematal gemmae are produced bothin vitroand in the wild (foliar gemmae are reported on plants in...

    • Philonotis marchica Bog Apple-moss
      (pp. 141-143)

      This small, pale green acrocarp forms turfs or scattered shoots to about 10 mm tall. The narrow leaves curve in one direction, are usually distinctly toothed, and are coated with a thin water-repellent cuticular wax that facilitates gas exchange when wet. It is dioicous and sporophytes (which are spherical, like an apple, hence the common name) are not known in Britain. Specialized asexual propagules are unknown in British plants. It behaves as a long-lived shuttle species, characteristic of long-lasting micro-sites.

      It occupies a narrow ecological niche, on friable sandstone rock where a more or less permanent surface water-film is present...

    • Physcomitrium eurystomum Norfolk Bladder-moss
      (pp. 143-145)

      This is a small ephemeral moss forming loose or closely packed turfs with shoots to 3 mm tall. The soft broadly oval leaves have a nerve that ends in a toothed, pointed apex. The capsule is characteristically urn-shaped with a small mitriform (shaped like a bishop’s hat) calyptra or cap (Physcomitriummeans ‘bladder cap’), and when mature the lid is shed to reveal a wide mouth (henceeury= widestomum= mouth) from which the spores are liberated. It is monoicous and sporophytes are abundant. Specialized asexual propagules are unknown. It shows an episodic life-history strategy, investing in high...

    • Plagiochila norvegica Bilobed Featherwort
      (pp. 145-147)

      This species is a green, moderately sized, turf-forming leafy liverwort with shoots to about 25 mm long and 4 mm wide. The slightly glossy and rather fragile leaves are bi-lobed with conspicuous teeth of varying size (some very large) around the margin; these characters separate it from the similar and widespread speciesP. porelloidesandP. spinulosa. Sporophytes and gametangia are unknown in British plants and specialized asexual propagules are absent; it behaves as a perennial stayer.

      It occurs on a single flint stone on a calcareous, wooded NE-facing slope, under an open canopy of Ash, Hazel and planted conifers...

    • Plasteurhynchium meridionale Portland Feather-moss
      (pp. 147-148)

      Formerly in the genusEurhynchium, this moss is a green or yellowish-green, densely branched mat-forming pleurocarp with numerous erect branches attaining 2 cm or more in length and 2 mm wide. The broadly triangular, widely spreading, somewhat undulate leaves appear lightly pleated lengthways (plicate), taper to a long, fine point with a finely toothed margin. It is dioicous and sporophytes are unknown in Britain. It behaves as a perennial stayer.

      It is a coastal plant, favouring warm, open or sheltered spots, growing on thin soil overlying limestone rocks, on tracks and stony banks, in disused quarries and in open, short...

    • Pseudocalliergon turgescens Turgid Scorpion-moss
      (pp. 148-150)

      This is a striking moss, with sparsely branched shoots up to 25 cm long (but normally much shorter) and some 2–3 mm wide when dry, swelling to 4−5 mm when moist. It is a glossy golden-green colour when moist, turning a bronzed shade of green when dry. The densely overlapping leaves are broad and concave with a small blunt point, tightly clasping the stem, giving a worm-like appearance. It is dioicous and sporophytes are unknown in Britain, and are extremely rare in Europe. In N America and Europe the species is often propagated vegetatively by readily detached shoot apices,...

    • Rhynchostegium rotundifolium Round-leaved Feather-moss
      (pp. 150-152)

      This moss is a dullish-green mat-forming pleurocarp with creeping shoots to about 2 cm long and irregular ascending branches about 1 mm wide. The soft oval leaves, shortly pointed and with a nerve that extends to just beyond mid-leaf, are slightly twisted when dry but are flat and spreading when moist. It is monoicous and sporophytes are commonly produced. Specialized asexual propagules are absent and it behaves as a perennial stayer.

      The plant grows in two distinct habitats: on the shaded boles and exposed roots of hedgerow trees including Ash and Field Maple along a farm track, and on shaded...

    • Riccia bifurca Lizard Crystalwort
      (pp. 153-154)

      This is a greyish-green thalloid liverwort forming, like others of its genus, small rosettes; in this species the rosettes are between 0·5 and 15 mm diameter and sometimes coalesce to form mats. The nameRicciadates from 1729, and is dedicated to the amateur Italian botanist and politician Pietro Francesco Ricci, andbifurcarefers to the forked rosettes forming roughly two halves. The thallus lobes are ‘branched’ 1–3 (5) times and each is no more than 1 mm wide. The key field character is the brown or orange-brown older regions of the thalli, which also become channelled with age....

    • Riccia canaliculata Channelled Crystalwort
      (pp. 154-155)

      This thalloid liverwort (seeR. bifurca page 153for an explanation of the origin of the nameRiccia) forms partial bright green or yellowish, sometimes violet-tinted rosettes or intricate mats up to 20 mm diameter with thin linear thalli that fork several times; the ultimate branches are usually less than 1 mm wide. It differs from most otherRicciain the long, narrow branches that taper at their ends with a distinct median groove (hencecanaliculata, referring to the channelled thalli), a character that is more conspicuous upon drying. It also has scales on its underside that curl over the...

    • Riccia nigrella Black Crystalwort
      (pp. 156-157)

      This is a small thalloid liverwort (seeR. bifurca page 153for an explanation of the origin of the nameRiccia) forming semi-circular or nearly circular rosettes to 15 mm in diameter; individual rosettes may coalesce to form mats. It is distinguished by the dark, bluish-green sharply furrowed thallus often with purplish-black margins. The key field character is the almost black (nigrella= black) scales on the underside that when desiccated curl up over the thallus. It is monoicous and sporophytes are common; the capsules are embedded in the older parts of the thallus and seen as dark spots. Specialized...

    • Scopelophila cataractae Tongue-leaved Copper-moss
      (pp. 157-159)

      This plant, one of the so-called copper mosses, is a bright to olive-green tuft-forming acrocarp. When growing luxuriantly it can form cushions to 30 mm deep, but usually it is much less. The somewhat glossy sharply keeled leaves, golden-bronze when old or exposed to the sun, are little more than 1 mm long, widest just above the middle and with a strong nerve that ends in the abruptly tapering apex. Superficially it resembles the common mossBarbula convolutabut this is a distinctly yellow plant.Scopelophila cataractaeis dioicous and sporophytes are unknown in Europe and only male plants have...

    • Seligeria brevifolia Short Rock-bristle
      (pp. 159-160)

      This is a minute, light-green moss forming loose turfs with shoots to 1mm tall. The narrow, rather short leaves (hencebrevifolia) have an indistinct nerve ending below the blunt leaf tip. It is monoicous with inverted pear-shaped capsules on short setae produced in abundance. Specialized asexual propagules are unknown and it behaves as a colonist. The genus commemorates Ignaz Seliger (1752−1812), a Silesian pastor, notary and florist.

      In England the plant grows in recesses in vertical Millstone Grit or sandstone rock faces in moist shaded moorland sites at moderate altitudes (around 400 m). Elsewhere in the BI it grows under...

    • Seligeria carniolica Water Rock-bristle
      (pp. 160-162)

      This is a minute moss, only 2–3 mm tall, which was originally described from Carniola (within modern day Slovenia) in 1882. It has bristle-like leaves that taper abruptly from an oval base to a long point, filled largely by nerve; they are directed to one side and curve downward in a wide arch. It is monoicous but sporophytes are rare. The characteristic ‘top-shaped’ capsule, held on a stout seta, has 16 short peristome teeth that radiate out like the spokes of a wheel, giving the moss its former nameTrochobryum carniolicum(trocho= wheel like). The capsule lid remains...

    • Seligeria diversifolia Long Rock-bristle
      (pp. 162-163)

      AllSelgeriaare tiny, and this species is no exception (for derivation of name, seeS. brevifoliapage 159). It is a yellow-green acrocarp forming loose turfs with shoots to 2·5 mm tall. The leaves increase in size up the stem (hencediversifolia, referring to leaves of different size), the uppermost are about 2 mm long in sterile shoots and they taper to a bluntly pointed tip that lacks teeth. It is monoicous and the abundant ovoid capsules are held on a straight seta 2–4 mm long (as opposed to no more than 1·5 mm long inS. brevifolia). Specialized...

    • Solenostoma caespiticium Delicate Flapwort
      (pp. 163-165)

      This plant, formerly known asJungermannia caespiticia, is a yellowish to pale green leafy liverwort that forms smooth mats with individual shoots reaching 5 mm long to 1∙2 mm wide. The closely overlapping leaves, inserted on either side of the stem, are more or less round and sometimes slightly concave. It is dioicous and perianths and sporophytes are rare in Britain. Specialized asexual propagules are often present as dense apical clusters of green unicellular gemmae surrounded by 1–2 pairs of strongly concave leaves. The rather variable shaped gemmae have an endogenous origin within the stem apex, a unique feature...

    • Southbya nigrella Blackwort
      (pp. 165-167)

      Southbya, named in honour of Anthony Gapper Southby (1799–1883) of Bridgwater, Somerset, is a genus of small leafy liverworts with opposite rounded leaves that is represented in Britain by two species. This species has creeping shoots no more than 5 mm long and less than 1 mm wide. It often forms intricate but sparse mats, with light green shoot tips and characteristically dark green older parts. When dry the leaves furl exposing black scaly undersides (hencenigrella). It is monoicous and sporophytes are fairly frequent. Asexual propagules are unknown. It behaves as a pioneer species, with a high investment...

    • Southbya tophacea Green Blackwort
      (pp. 167-168)

      Named by the intrepid explorer and naturalist Richard Spruce (1817–1893) after its predilection for sandy soils (Latintophaceusmeaning sandy or gritty), this species is a small creeping leafy liverwort with shoots not more than 6 mm long and 1 mm wide. It has opposite, oval to round leaves that overlap and nearly touch above the stem when moist. It closely resemblesS. nigrella(page 165) but it is normally a lighter green or a pale yellowish-brown colour, not the characteristic dark green to black colour of that species. The moss is dioicous and sporophytes are fairly frequent. Asexual...

    • Sphagnum balticum Baltic Bog-moss
      (pp. 168-170)

      This species forms brownish or orange, loosely packed turfs comprising slender upright stems to 15 cm tall. The bog-mosses are usually immediately recognized by their distinctive growth form, in particular the capitulum (head) of short, densely arranged branches atop a weak stem that carries numerous clusters (fascicles) of limp branches with leaves that closely overlap, often in neat ranks. Bog-mosses are considered unrelated to other ‘true’ mosses and are placed in a class of their own, the Sphagnopsida.Sphagnum balticumis a member of section Cuspidata with spreading stem leaves and bunches of three branches (fascicles) on a pale stem....

    • Splachnum vasculosum Rugged Collar-moss
      (pp. 170-172)

      This is a pale to dark green tuft-forming moss with shoots to 7 cm tall. The soft glossy leaves are broad, almost round, with a nerve that ends below the short, bluntly pointed apex. It is dioicous and like other members of the family it has a distinctive capsule. The apophysis (the base of the capsule) is conspicuously inflated and forms an almost globular dark purple structure that is wrinkled and pitted when dry. Held aloft on a thin red seta, it releases volatile aromatic compounds and provides visual cues to attract flies that facilitate spore dispersal (entomophily). The spores...

    • Telaranea europaea Irish Threadwort
      (pp. 172-174)

      This is a delicate, yellowish-green leafy liverwort forming smooth glistening mats of very slender, interwoven shoots that are 15–25 mm long and barely 1 mm wide.Telaraneais from the Latintela(web) +aranea(spider or spiders’ web) alluding to the delicate cobweb-like appearance of the shoots. The leaves consist of, usually, three hair-like erect leaf lobes one cell wide inserted on a basal lamina that is only half a cell high; underleaves are present but very tiny. It is monoicous and sporophytes are fairly frequent. Specialized asexual propagules are present in the form of club-shaped multicellular bulbils...

    • Telaranea murphyae Murphy’s Threadwort
      (pp. 174-175)

      This is a tiny yellowish-green to dark green leafy liverwort forming wefts of slender intertwined shoots 20–30 mm long and barely 1 mm wide. The leaves consist of usually four hair-like erect leaf lobes one cell wide inserted on a basal lamina that is up to 3∙5 cells deep (as opposed to half a cell deep in the Red ListedT. europaea, page 172). It is dioicous but only male inflorescences are known. Specialized asexual propagules are unknown and it behaves as a colonist.

      It grows on damp peat, humus and sandy soils, on leaf-litter, decorticated logs and stumps,...

    • Thamnobryum angustifolium Derbyshire Feather-moss
      (pp. 175-177)

      This moss is a medium-sized pale green pleurocarp forming rough dendroid mats, sometimes lime-encrusted, with shoots up to 4 cm long. Scale-like stem leaves are triangular, whereas the branch leaves are narrow (henceangustifolium) and linear with a thick nerve and coarsely toothed margins. The leaves, seen in transverse section under the microscope, are more than one layer of cells thick (multistratose), a feature shared by the Red ListedT. cataractarum(page 178). It superficially resembles the commonT. alopecurumbut in that species the leaves are broader and only one cell layer thick with a thinner nerve and smaller...

    • Thamnobryum cataractarum Yorkshire Feather-moss
      (pp. 178-179)

      This species is a medium-sized, dark green to blackish moss forming rough mats with dendroid shoots up to 5 cm long. The scale-like stem leaves are triangular whereas the branch leaves are narrow and parallel sided with a very wide nerve and with obscurely toothed margins. The branch leaves are often eroded away leaving a tangle of stiff wiry stems. The leaves, as seen in transverse section under the microscope, are more than one cell layer thick (multistratose), a feature shared by the Red ListedT. angustifolium(page 175). Gametangia (male and female parts) and sporophytes are unknown. Specialized asexual...

    • Timmia megapolitana Indian-feather Moss
      (pp. 179-181)

      Timmia, commemorating the German botanist J. C. Timm (1734–1805), is a taxonomically isolated genus of moss consisting of only four species worldwide, of which three occur in the BI. Only one,T. megapolitana, occurs in England. This species is a green to yellowish-green acrocarp, often covered in silt, forming compact or loose tufts with individual shoots to 4 cm tall. The specific epithetmegapolitanarefers to a region in NE Germany, although it was not originally collected from there. The relatively long leaves, up to 8 mm, taper to a fine point and have coarse single teeth along the...

    • Tomentypnum nitens Woolly Feather-moss
      (pp. 181-183)

      This moss is a moderately robust, yellowish-green to golden-brown pleurocarp forming rough mats or scattered shoots to 10 cm long. The stems are creeping or ascending and a dense brownish tomentum (covering of rhizoids) gives the lower stem a woolly appearance (Tomentypnummeans aHypnumwith tomentum). Rhizoids also occur on the back of the nerve at the leaf base. The shiny (hencenitens) leaves are narrowly triangular, tapering to a fine point and have several longitudinal folds (plicate). It is dioicous and sporophytes are rare. Specialized asexual propagules are unknown and it behaves as a perennial stayer.

      It grows...

    • Tortula cernua Flamingo-moss
      (pp. 183-185)

      This moss is a small, bright green acrocarp forming tufts that are sometimes 10–30 cm across and between 3–5 mm tall. Its leaves, variable in shape, gradually taper from the base to a long pointed apex or are broadest above middle. The leaf margins are recurved and bordered by narrow elongate cells and the nerve extends beyond the apex. The leaves twist when dry, but spread when moist. It is monoicous and sporophytes are common. Specialized asexual propagules are unknown and it behaves as a short-lived shuttle species. It is the distinctive curved and slightly drooping (hencecernua)...

    • Tortula cuneifolia Wedge-leaved Screw-moss
      (pp. 185-186)

      This moss is a small, bright green acrocarp forming low tufts or scattered shoots less than 5 mm tall. The soft concave leaves are variable in shape but typically are wedge-shaped and widest above the middle (hencecuneifolia); the plain margins lack a differentiated border and have a nerve that projects just beyond the leaf tip as a short or sometimes longer yellowish or silver hairpoint. Braithwaite (1887) notes that the older leaves tend to lose their chlorophyll and become diaphanous (translucent). This is one of a number of similar lookingTortulaspecies including the Red ListedT. solmsii(page...

    • Tortula solmsii Solm’s Screw-moss
      (pp. 186-188)

      This moss, named after the German botanist H. Solms-Laubach (1842–1915), is a small yellowish-green tuft-forming acrocarp with shoots up to 2∙5 mm tall, usually less. The leaves are somewhat twisted when dry and spreading when moist, widest above the middle with a nerve that ends immediately below, or slightly projects beyond, the rounded leaf tip. It is dioicous and capsules are occasionally produced. Vegetative propagules are unknown and it behaves as a colonist.

      It is a coastal plant growing on neutral to slightly basic soils, on low sandstone cliffs, moist roadside banks and on thin soil in crevices of...

    • Tortula vahliana Chalk Screw-moss
      (pp. 188-189)

      This moss is a small bright green acrocarp forming pure turfs or scattered shoots no more than 5 mm tall. Typically it has spoon-shaped leaves, widest above the middle, and a nerve that extends beyond the rounded leaf tip as a short greenish hair point. It is monoicous and sporophytes are frequent but very few appear to reach maturity in Britain possibly due to late spring frosts. Asexual propagules in the form of protonemal gemmae have been reported (Whitehouse, 1987) and irregular shaped rhizoidal tubers are known from Belgium (Andriessonet al., 2002). It is a pioneer colonist.

      It grows...

    • Tortula wilsonii Wilson’s Pottia
      (pp. 190-191)

      This moss, named in honour of the acclaimed bryologist W. Wilson (1799–1871) who first found it, is a small, bright or pale green acrocarp forming low turfs or solitary shoots less than 5 mm tall. The oval leaves, widest just above the middle, have recurved margins and a nerve that runs beyond the gradually tapering leaf apex to form a short hair point. Recently transferred from the genusPottiaintoTortula(meaning spirally twisted peristome teeth), it is superficially similar to several other ‘pottioid’ species and it can be difficult to identify in the field. It is monoicous and...

    • Weissia levieri Levier’s Beardless-moss
      (pp. 191-192)

      Named in honour of the Swiss botanist Emile Levier (1839–1911), this moss is a small, dull green turf-forming acrocarp no more than 10 mm tall, often less. The nerved leaves are strongly curled when dry and spreading when moist, gradually increasing in size up the stem and are flat (plane) to slightly incurved in their upper part. The plant is monoicous and sporophytes are common. The capsule is on a short seta and partially hidden amongst the uppermost leaves; uniquely within the subgenus (Astomum) it has a deciduous lid providing a useful field character, but microscopic confirmation is needed....

    • Weissia multicapsularis Many-fruited Beardless-moss
      (pp. 192-194)

      This moss is a yellowish-green tuft-forming acrocarp up to 15 mm tall. The genusWeissia, named after the German botanist F. W. Weiss (1744–1826), is distinctive but naming to species level is not always easy. Recent studies using molecular markers (a gene or DNA sequence with a known location on a chromosome) support the view thatW. multicapsularisis a good species (Conyers, Conyers & Laybourn, 2012). The leaves are flat (plane) or only very weakly incurved in their upper part, with an abrupt transition between the short lower leaves and longer uppermost leaves. It is monoicous and sporophytes are...

    • Zygodon forsteri Knothole Yoke-moss
      (pp. 194-196)

      Named after the botanist and plant illustrator T. F. Forster (1761–1825), this moss is an acrocarp that forms small, dark green to blackish cushions with shoots to 5 mm tall. The narrowly ovate leaves, slightly twisted when dry and spreading when moist, have plane untoothed margins and a nerve that extends beyond the tip in a short point. It is monoicous and sporophytes are common. Asexual propagules (gemmae) are formed on the protonema enabling short-distance dispersal on the same tree and perhaps between trees (Adams & Rumsey, 2005); leaf fragmentation may also aid spread. It behaves as a colonist.

      It...

    • Zygodon gracilis Slender Yoke-moss
      (pp. 197-198)

      This is a golden-brown, turf-forming acrocarp with shoots 2–6 cm tall, much larger than other members of the genus. The narrow leaves are sharply toothed at the tip, twisted when dry and recurved when moist. It is dioicous and sporophytes are very rare. Specialized asexual propagules are unknown in nature, although protonemal gemmae have been observed in culture. It is said to be a colonist.

      It grows on Carboniferous limestone dry-stone walls at 270–520 m a.s.l., mostly on N- or NW-facing aspects where colonies intercept mist and rain; more rarely, it grows on natural rock outcrops (in contrast...

  11. Losses – the English extinctions
    (pp. 199-205)
  12. APPENDIX 1: British Red List species with post-2000 Welsh and Scottish records but not seen in England for over 50 years (Hill et al., 2008)
    (pp. 206-206)
  13. APPENDIX 2: Species’ Status Summary
    (pp. 207-211)
  14. Glossary
    (pp. 212-214)
  15. References
    (pp. 215-221)
  16. Acknowledgements
    (pp. 222-222)
  17. Index
    (pp. 223-224)