Shrubby green tufts of narrow, cylindrical branches with basalattachment point distinctly blackened. Col: pale green to grey-green.Isid/sored: small rounded soralia that often develop tiny isidia (justvisible x10). Fr: occasionally present, rounded pale greenish withdistinctive long marginal spines. Lower: not applicable. Similar to:short-tufted types of Strap lichens Ramalina species or Evernia prunastri(all have flattened, strap-shaped branches). Also see Usnea hirtaNotes: the commonest shrubby Usnea species with a blackened baseoccurring in pinewoods and drier birchwoods, and the only Usnealikely to be found fertile in Scottish pinewoods.
Short pale green tufts of narrow, flattened branches with discreteoval soralia. Col: pale yellow-green to pale grey-green. Sored:discrete oval soralia along branch margins. Fr: rare. Lower: samecolour as upper. Note: Ramalina species are generally moreabundant on nutrient rich bark, especially on branches/twigs, but R.farinacea is the most common species on tr ees with acidic bark.Similar to: short-tufted types of Usnea species (Beard lichens,which have cylindrical branches). Also see Evernia prunastri.
Short yellow-green tufts of flattened branches with f orked tips andirregular soralia; often with a network of ridges. Col: pale yellow-green to pale grey-green. Sored: at first round, on ridges and lobemargins; later irregular, spreading and coalescing. Fr: very rare.Lower: whitish, occasionally with green patches. Note: acommon species on a range of deciduous tr ees. Similar to:Ramalina farinacea (narrower lobes; upper and lower surfaces thesame colour).
Shrubby grey-green, often densely shaggy tufts with numerous longspine-like isidia and a pale basal attachment point. Col: grey-green.Isid: numerous long spine-like isidia. Fr: occasionally present,rounded pale greenish with distinctive long marginal spines.Lower: not applicable. Similar to: U. subfloridana (soralia, distinctlyblackened base). Also Ramalina species, Evernia prunastri and otherUsnea species (refer to U. subfloridana description). Notes: verylimp when wet. Very common on birch and pine in easternpinewoods. Scarce in the west.
Elongated green tufts (to c . 30cm) like fish bones hanging frombranches/trunks due to distinctive branching pattern. Col: grey-green to yellow-green. Isid/sored: isidia develop on soredia oron warts, mostly on the main stem (x10). Fr: very rare. Similarto: short forms can be mistaken for other Usnea species. Note:mainly on pine and birch.
AWI NS Elongated pale yellow-green tufts of very narrow, hair-likebranches with elongate pseudocyphellae (x10). Col: pale yellow-green, to creamy yellow. Isid/sored: absent. Fr: rare. Similar to:when hanging from branches easily mistaken for Usnea filipendula. U.filipendula has isidia and if you gently pull the strands lengthwise theyare stretchy due to a springy central strand (like knicker-elastic);Alectoria has no such springy central strand. Note: on pine, birchand alder in old pinewoods.
Elongated green-brown tufts of very narrow, hair-like brancheswith discrete soralia. Col: greenish brown, brown to dark brown.Sored: discrete oval soralia along branches. Fr: very rare.Similar to: other Bryoria species but B. fuscescens is by far thecommonest.
Sphaerophorus globosus A Coral Lichen Usnea filipendula Fishbone Beard Lichen
Guide 1: Leafy and shrubby lichens on pine, birch, alder and deadwood
Fruits on Hypogymnia physodes
Isidia on Pseudevernia furfuracea
Soredia on Hypogymnia physodes
Marginal soredia on Tuckermanopsis chlorophylla
Rhizines on Hypotrachyna laevigata
Key features
The use of a hand lens (pr eferably of x10 magnification) is recommended to examine andappreciate some of the key features of the lichens in this guide . A (x10) in the text indicateswhen a hand lens is necessar y.
ColourThe colour of upper (and if visible the lo wer) surface can be very variable between wet and dry states.In this guide, the descriptions are for dry lichens unless otherwise noted.
Growth form of the thallus (the main body of the lichen)Leafy (foliose): thallus consists of leafy lobes. Lobes may be loosely attached or adpressed(closely pressed) to the substrate.
Squamulose: thallus consists of tiny lobes or leaf-like scales (squamules). The squamules mayoverlap like roof shingles and are not always obvious (they can appear crustose to the naked eye).
Shrubby (fruticose): thallus often tufted; composed of narrow cylindrical, or flattened strap-shaped branches.
Crustose: thallus is a crust that may be thin, thick, smooth, wrinkled, powdery, granular or crackedlike dried mud. Crustose species are adpressed (closely pressed) to the substrate. Some specieshave concentric growth rings at the margin.
Features that may be present on the upper surfaceFruits: sexual reproductive structures that produce spores. They can be round discs, pimple-likeor globular. They can be brownish, pinkish, orange-brown or black, and may have a margin that isthe same colour as the thallus (a thalline margin).
Isidia: tiny thallus projections (x10) that are involved in vegetative reproduction. They may benodular, granular, finger-like, or branched like tiny fragments of coral (coralloid). Eroded orgranular isidia can be mistaken for granular soredia.
Pseudocyphellae: pores or cracks that expose the interior of the thallus and so a ppear as palerspots or lines. Pseudocyphellae on the upper surface ma y develop soredia.
Soredia: floury powder or coarse granules (like caster sugar, x10) that are involved in vegetativereproduction. They often occur along ridges or cracks on the surface , or on thallus margins, andmay be diffuse or arise in discr ete structures (soralia).
Features that may be present on the lower surface Rhizines: root-like structures that can be thick and fluffy, thin and wiry, pale or dark. Under ahand lens (x10) they can appear simple, forked or branched.
Abbreviations for features that are used in the species descriptionsAWI = Ancient Woodland Indicator species, NS = Nationally Scarce, Col = colour, Isid = isidia,Sored = soredia, Fr = fruit, Lower = lower surface.
Further information
BooksLichens: An Illustrated Guide to the Br itish and Ir ish Species. Frank Dobson. 5th Edition (2005). RichmondPublishing Co. Ltd. This is the best identification guide to most of the common lichens of a range of habitats.Lichens. Oliver Gilbert (2000). Collins New Naturalist series. Harper Collins, London. This is a highlyreadable account of lichen ecology and habitats in Britain including a g ood chapter on woodland lichens.Lichens of Atlantic Woodlands Guides: 1 and 2. Plantlife Scotland (2008). Two water resistant fold-out fieldguides to lichens in Atlantic woodlands.The Montane Heathland Lichen Guide. Andrea Britton (2008). Macaulay Institute, Aberdeen. A useful fieldbooklet that includes a number of the lichens that are commonly found on the forest floor in pinewoods.
Information and advicewww.bls.org.uk The British Lichen Society (BLS) has inf ormation on lichens, publications, coursesand web links. www.nwdg.org.uk The Native Woodland Discussion Group (NWDG) runs courses onwoodland lichens.www.britishlichens.co.uk The britishlichens website has useful photos of many British species.
Irregularly branched, pale greyish/brownish cylindrical stems, thoughthese can be grazed (e .g. by deer) to form neat dense cushions.Col: pale grey to pale green-grey, main branches often orange-brown. Isid/sored: none. Fr: occasional; globular swellings atbranch tips burst to reveal a dark powder of spores. Similar to:The AWI species Bunodophoron melanocarpum can occur on oldpine, birch and alder in western pinewoods; it has more flattenedstems than S. globosus (see The Lichens of Atlantic Woodlands: Guide 2).
The central elastic strand in Usneaspecies (e.g. U. filipendula)
AWI Pale grey smooth, narrow lobes with square-cut tips anddiscrete soralia. Col: pale grey to pale blue-grey. Sored: in discreteglobose soralia at lobe tips. Fr: scarce; dark brown disc, thallinemargin. Lower: black with numerous branched black rhizines (x10).Similar to: H. taylorensis (no soredia - see The Lichens of AtlanticWoodlands: Guide 2). H. revoluta Powdered Loop Lichen (has diffusesoralia and distinctly down-turned lobes with rounded tips; it is moretypical of less acidic Parmelion communities). Note: typical of theParmelion community. Common in the west, absent from the east.
Pale grey lobes with isidia that may form a network on raisedridges (surface can have a hammered appearance). Col: pale greyto pale green-grey, often with brownish lobe tips. Isid: simple tocoralloid isidia, often brown-tipped (x10). Fr: occasional; red tobrown disc, thalline margin with isidia. Lower: black, brown atmargin; numerous simple (occasionally forked) black rhizines.Note: very common in a range of lichen comm unities. Atraditional source of dye.
Pale grey lobes with soralia and oval to elongated palepseudocyphellae that may form a network on raised ridges(surface can have a hammered appearance). Col: pale grey topale green-grey, often with brownish lobe tips. Sored: developalong pseudocyphellae. Fr: occasional; red to brown disc, thallinemargin with soredia. Lower: black, brown at margin; numeroussimple (occasionally forked) black rhizines. Note: very commonin a range of lichen communities. A traditional source of dye.
Narrow strap-shaped grey lobes (can appear shrubby), withforked, antler-like branches, dark grey-black lower surface anddistinctively forked branches. Col: grey. Isid: often abundant,giving the thallus a bristly appearance. Fr: scarce, olive to browndisc with thalline margin. Lower: usually black or mottled blackand brownish-white; sometimes pinkish. Note: very common inPhysodion communites. Also known as Antler Lichen.
Pale greenish-whitish frilly lobes with wavy divided margins. Col:pale grey-green to whitish green, sometimes brownish. Old partsof thallus often with reddish/pinkish patches. Isid/sored: oftenwith simple to coralloid isidia or gran ular soredia on margins. Fr:very rare. Lower: brown, white or black; rhizines simple orbranched, few or absent. Note: very common in several lichencommunities. Similar to: Platismatia norvegica (see above).
Brown to olive-brown (olive green when wet) with pale greyishsoredia along raised wavy margins. Col: brown, olive-brown toolive-green, greener when wet. Sored: along margins. Fr: rare.Lower: paler brown than upper, with sparse pale rhizines. Note:most common in Physodion communites in the east. Similar to:brown forms of Platismatia glauca but brown forms of P. glaucaremain brown when wet.
Pseudevernia furfuracea Tree Moss Platismatia norvegica Old Growth Rag Lichen
Tiny, very narrow (to 1mm wide) closely adpressed lobes thatare matt pale greyish. Often forming neat rosettes(‘starbursts’). Col: matt pale grey to blue-grey but lobe tipsoften shiny). Sored: pale grey to blue-grey. Discrete orforming a crust. Fr: rare. Lower: brown-black, with simplerhizines. Similar to: Imshaugia aleurites (has isidia, thallusoften shiny x10) and P. ambigua (yellow-green). Note: onpine, pine lignum, birch.
Tiny, very narrow (to 1mm wide) closely adpressed lobes that arematt yellow-green. Often forming neat rosettes (‘starbursts’).Col: matt yellow-green. Sored: yellow-green. Discrete or forminga crust. Fr: rare. Lower: brown-black, with dark simple rhizines(x10). Similar to: P. hyperopta (pale grey) and to a smallHypotrachyna sinuosa (discrete soralia on raised lobe tips; lowersurface with branched black rhizines). Note: on pine, pine lignum,birch. P. ambigua is much more common in the east than the w est.
Very narrow yellow-green lobes with rhizines usually visible as ablack ‘fuzz’ at lobe edges. Col: yellow-grey to yellow-green.Sored: often with discrete globose soralia on raised lobe tips.Fr: not known. Lower: black, with numerous branched blackrhizines (x10). Similar to: Parmeliopsis ambigua (sorediascattered over thallus rather than on raised lobe tips; rhizinesnot readily visible at lobe edges). H. laevigata (not yellowish).Note: mainly in western woods on acidic bark and lignum.
2 TINY LEAFY LICHENS
Imshaugia aleurites Spiky Starburst Lichen
Parmeliopsis ambigua Green Starburst Lichen
IntroductionThis Plantlife field guide is for anyone interested inidentifying some of the more conspicuous lichens found inScottish native pinewoods. It looks at leafy and shrub bylichens that grow on trees with very acidic bark and on deadwood. A companion guide (Lichens of Scottish pine woods:Guide 2) looks at scaly and crustose lichens found in thesehabitats and at lichens found on trees and shrubs with lessacidic bark such as rowan.
What are Scottish pinewoods?They are semi-natural woodlands containing a significant proportionof Scots pine and often including dead pine . Scots pine and/or birchmay be the dominant tree species, and there is often some rowan,and more locally, alder and willow. Some pinewoods may also haveaspen, hazel, oak and, especially in the east of Scotland, anunderstorey of juniper.
What is a lichen?A lichen is an association between a fungus and a photosyntheticpartner. The fungus forms the main body of the lichen (the thallus),usually including a protective, opaque upper surface that can be gr een,yellow, orange, reddish, brown, grey, whitish or bluish. Thephotosynthetic partner manufactures food using the energy of sunlight(photosynthesis). In most lichens the photosynthetic par tner is a greenalga, but some lichens have a cyanobacterium (blue-green alga).
Mosses and liverworts often grow with lichens. They have greenchlorophyll but no pigmented protective upper surface, and mostspecies are semi-translucent green or yellowish green, although someare reddish purple. Unlike lichens, mosses and most liverworts havea stem with leaves, although some liverworts consist of a thallus thatcould be mistaken for a lichen.
Why are lichens of Scottish pinewoods important?Lichens are important for biodiversity and as indicators of habitatquality. There are around 1850 species in the British Isles comparedto around 1400 species of native flowering plants. Scottishpinewoods support a number of specialist pinewood lichens that arerare elsewhere in Britain.
Most lichens prefer clean air, and require habitats that are notregularly disturbed. The woods with the most diverse lichen florahave a varied topography, including river valleys, and a diversewoodland structure with glades and a range of tr ee and shrub speciesincluding old trees and shrubs. In areas with historically low levels ofpollution some well-developed pinewood lichen communities may begood indicators of ancient woodland.
Lichen communitiesDistinctive lichen communities in pinewoods include:
The Calicion (the ‘pinheads’): This community is a specialistcommunity found on very dry bark, bark recesses or deadwood that iseither not exposed to direct rainfall or dries very quickly (e.g. stumpssheltered from direct rainfall, pine snags and standing pine ‘bones’). It istypically dominated by thin crustose species, some of which have tinystalked fruits that resemble stubble or pinheads under a hand lens.
The Parmelion: In this guide the Parmelion refers to the Parmelionlaevigatae community. It is best developed in the west of Scotland ontrees with very acidic bark such as alder and bir ch and is absent fromthe eastern pinewoods. It is typically dominated by grey, leafy andcrustose lichens including the Smooth Loop Lichen Hypotrachynalaevigata. The Parmelion community is dealt with more fully in TheLichens of Atlantic Woodlands: Guide 2 (Acton & Griffith, for PlantlifeScotland, 2008).
The Physodion: This is a typical community found on pine bark andlignum and, in the east and central pine woods, is very common onother trees with very acidic bark such as birch and alder. It istypically dominated by grey and brown leafy lichens, grey crustose
lichens and brown filamentous lichens that look like hair. It can bevery similar to the Parmelion community but in the Physodioncommunity the brownish Hair lichens (Bryoria species) are generallymuch more common.
The Lobarion: The Lobarion can occur on mildly acidic bark butthis community is scarce in eastern pinewoods. It is mainlyassociated with old rowan and rain seepage tracks below damagedbark of old birch but, if present, other tree and shrub species such ashazel, aspen, willow or old oak can be impor tant. Five species aredescribed in this guide: Nephroma laevigatum, Degelia plumbea andthree Lobaria species. The Lobarion community is best developed inAtlantic woodlands and is dealt with more fully in The Lichens ofAtlantic Woodlands: Guide 1 (Acton & Griffith, for Plantlife Scotland,2008).
The Usneion: This community is typically found occurring asgreenish shrubby tufts, especially on branches and twigs in thecanopy. Greenish shrubby lichens (Strap lichens, Oak Moss andBeard lichens) are frequent on twigs and branches of broadleavedtrees in unpolluted areas. The Beard lichens (Usnea species) aredifficult to identify, often requiring chemical analysis.
Important lichen micro-habitatsThe lichens in Scottish pinewoods are associated with severalmicro-habitats:
• Trees and shrubs with very acidic bark, for example, pine,birch, alder and non-native conifers.
• Trees and shrubs with less acidic bark , for example, rowan,aspen, willow, hazel and on bark along rain seepage tracks belo wdamaged areas of old birch.
• Deadwood: Dry, well-lit but sheltered wood without bark(lignum) is hard and rots slowly. A number of specialist pinewoodspecies are associated with standing dead pines, leaning or fallendead pine trunks and dead limbs still attached to living pines.Many are tiny specialist species and identification requiresmicroscopic examination. However, identifying their micro-habitats and the presence of the Calicion (‘pinhead’) community(by careful searching for tiny lichens that resemble stubble orpinheads) is relatively easy. In contrast, damp, shaded pine lignumrots relatively quickly and these habitats (e .g. rotting trunks alongthe ground and well rotted stumps) can support a number ofcommon and widespread lichens (e.g. Cladonia species) thatnormally grow on the ground (terricolous lichens). This guidedoes not deal with these ter ricolous species.
Lichen hunting!This is the fun bit! Arm yourself with a hand lens and explor e arange of woodland habitats, such as old pines (including an y ‘granny’pines, dead standing and fallen pines), tree stumps, old birch, oldrowan, riparian woods and wet woodlands. The occurrence of palegrey, pale blue-grey to pale green-grey leafy lichens, whitish crustsand brownish Hair lichens on tree trunks is a good indication of thepresence of the Physodion or Parmelion communities. The uppercanopy will often have a well-developed Usneion community ofshrubby green Beard and Strap lichens. An ancient pinewood willoften have good populations of a range of the species illustrated inthis guide, including some specialist pinewood species that areancient woodland indicators (AWI species). Some of the speciesdescribed have a restricted distribution (e.g. some are common inthe east of Scotland and absent in the w est or vice versa), and someare quite rare. Happy hunting!
Although common names have been used in this guide , few commonnames for lichens are universally accepted. Scientific names shouldalways be used when recording lichens to avoid ambiguity.
AWI Tiny narrow (1-3mm wide) whitish to pale grey, often shinylobes with grey to brownish-grey isidia. Often closely attached tosubstrate and forming rosettes (‘starbursts’). Col: pale grey, edgesand lobe tips often tinged brownish. Isid: grey often with brownishtips, often abundant and sometimes forming a crust. Fr: uncommon;red-brown disc, thalline margin. Lower: pale brown with simplebrown rhizines. Similar to: Parmeliopsis hyperopta (has soralia, lowersurface dark). Note: on pine, pine lignum, birch.
Grey inflated hollow lobes, with lobe tips often raised to sho wbrown underside or split to reveal distinctive soralia. Col: palegrey to green-grey. Sored: lobe tips split, turn up and developsoredia on underside. Fruits: scarce; red-brown disc, thallinemargin. Lower: black, brown near margin; no rhizines. Similarto: H. tubulosa Tube Lichen (typically on twigs; narrow, tubularlobes and discrete globose soralia on lobe tips that do not split).The AWI species Menegazzia terebrata can occur on old birch andalder in western pinewoods but has distinctive holes in the thallus(see The Lichens of Atlantic Woodlands: Guide 2). Note: verycommon in a range of lichen comm unities. Also found on heatherthat is not regularly burned – hence Heather Rags.
AWI NS Pale grey-green rounded lobes with indented margins.Upper surface with very distinctive network of pale sharp ridges.Col: pale grey-green to grey-green, edges often tinged brownish. Isid:may be present on ridges. Fr: not seen in Britain. Lower: brown,white or black; rhizines simple or branched, few or absent. Note: arare species of old pine and bir ch woods on pine, birch, alder, oak androcks. Similar to: Platismatia glauca (more frilly, divided lobes – mayhave a network of ridges but they are not distinctively sharply ridged).Parmelia sulcata and P. saxatilis both have much smaller lobes (to 0.5cmwide) than P. norvegica (lobes to c. 2.5cm wide).
