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Key features
Fruits on Ochrolechia tartarea
with a thalline margin
The use of a hand lens (preferably of x10 magnification) is recommended to examine and
appreciate some of the key features of the lichens in this guide. A (x10) in the text indicates
when a hand lens is necessary.
Colour
The colour of upper (and if visible the lower) surface can be very variable between wet and dry states.
In this guide, the descriptions are for dry lichens unless otherwise noted.
Pinhead or Stubble lichens
Lobaria virens Green Satin Lichen
Nephroma laevigatum A Kidney Lichen
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 may
overlap 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 strapshaped
branches.
Crustose: thallus is a crust that may be thin, thick, smooth, wrinkled, powdery, granular or cracked
like dried mud. Crustose species are adpressed (closely pressed) to the substrate. Some species
have concentric growth rings at the margin.
Features that may be present on the upper surface
Fruits: sexual reproductive structures that produce spores. They can be round discs, elongated,
pimple-like or globular. They can be brownish, pinkish, orange-brown or black, and may have a
margin that is the same colour as the thallus (a thalline margin).
Isidia: tiny thallus projections (x10) that are involved in vegetative reproduction.They may be
nodular, granular, finger-like, or branched like tiny fragments of coral (coralloid). Eroded or
granular isidia can be mistaken for granular soredia.
Soredia: floury powder or coarse granules (like caster sugar, x10) that are involved in vegetative
reproduction. They often occur along ridges or cracks on the surface, or on thallus margins, and
may be diffuse or arise in discrete structures (soralia).
Abbreviations for features that are used in the species descriptions
AWI = Ancient Woodland Indicator species, NS = Nationally Scarce, Col = colour, Isid = isidia,
Sored = soredia, Fr = fruit, Lower = lower surface.
Further information
Publications
Lichens: An Illustrated Guide to the British and Irish Species. Frank Dobson. 5th Edition (2005). Richmond
Publishing 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 highly
readable account of lichen ecology and habitats in Britain including a good chapter on woodland lichens.
Acton,A. & Griffith,A. 2008, Lichens of Atlantic Woodlands: Guides 1 and 2, Plantlife Scotland 2008. Two water
resistant fold-out field guides to lichens in Atlantic woodlands.
The Montane Heathland Lichen Guide. Andrea Britton (2008). Macaulay Institute, Aberdeen. A useful field
booklet that includes a number of the lichens that are commonly found on the forest floor in pinewoods.
Contorted fruits of
Hypocenomyce friesii
Elongated fruits of Xylographa parallela
Isidia on Lobaria pulmonaria
Identifying pinheads to species level is beyond the scope of this guide but very careful examination with a x10 hand lens can reveal a number of
different forms with very long thin or short stubby stalks, white or yellowish frosting (e.g. of the upper stalk just below the pinhead), and reveal that
the heads can have a topping that is brown or black. A range of types with combinations of the above characters is likely to indicate the presence
of a number of different species. Many are AWI species and some species in pinewoods are Nationally Scarce (NS) or Nationally Rare.
2 LEAFY AND CRUSTOSE LICHENS ON OLD ROWAN (these species may also occur on
other trees and shrubs such as hazel, aspen, willow, old oak or old birch)
Lobaria pulmonaria Tree Lungwort
Lobaria scrobiculata ‘Lob Scrob’
wet
dry
AWI Green or brownish adpressed, smooth or wrinkled wavy
lobes with orange fruits arising from volcano-like warts. Col: dry =
green or brownish-green; wet = green. Isid/sored: none. Fr:
common; orange disc, thick green margin. Lower: even tomentum.
Similar to: Flavoparmelia caperata (paler more yellow green and
with soredia); L. amplissima (whitish when dry, and with brown
shrubby cauliflower-like growths on the surface, see The Lichens of
Atlantic Woodlands: Guide 1). Note: scarce in the east, much more
common in the west.
Degelia plumbea Plum-fruited Felt Lichen
AWI Grey or brownish lobes with distinctive fruits on underside
of upturned lobe tips. Col: dry = brown-grey to red brown; wet
= brown-grey to brown. Isid/sored: none, but often with tiny
flattened lobules. Fr: frequent; orange-brown to red-brown disc,
thin brown margin. Lower: smooth to wrinkled. Note: scarce in
the east, much more common in the west.
Thelotrema lepadinum Barnacle Lichen
LICHENS OF SCOTTISH
PINEWOODS
Guide 2: Crustose and scaly lichens on pine, birch and
alder, and lichens on trees with less acidic bark
Soredia on Ochrolechia androgyna
Information and advice
www.bls.org.uk The British Lichen Society (BLS) has information on lichens, publications, courses
and web links.
www.nwdg.org.uk The Native Woodland Discussion Group (NWDG) runs courses on
woodland lichens.
www.britishlichens.co.uk The britishlichens website has useful photos of many British species.
Advice and support
Plantlife Scotland can help you in your quest for information and support.
Plantlife Scotland, Balallan House,Allan Park, Stirling FK8 2QG
Tel: +44 (0)1786 478509 www.plantlife.org.uk scotland@plantlife.org.uk
© October 2009 ISBN 978-1-907141-11-9
Plantlife Scotland is part of Plantlife International – the Wild Plant Conservation charity, a charitable company limited by
guarantee. Registered charity no SC038951. Registered company no 3166339, registered in England.
This guide has been written and illustrated
for Plantlife Scotland by Andy Acton. All
photos © Acton/Griffith 2009.
wet dry wet
dry
AWI Green or brownish loosely attached lobes with distinctive
network of ridges (lung-like). Col: dry = green or brownish green;
wet = green. Isid/sored: often with soredia or isidia along ridges.
Fr: occasional; orange to red-brown disc, thin green margin.
Lower: tomentum patchy with convex naked areas corresponding
to depressions between the ridges on the upper surface. Note:
scarce in the east, much more common in the west.
AWI Yellowish or blue-grey loosely attached irregular lobes with
irregular ridges and grey soredia. Col: dry = matt creamy yellowish
green to yellowish grey; wet = blue-grey. Sored: grey to blue-grey;
round, then elongated, irregular and spreading along ridges and lobe
margins. Fr: rare; red-brown disc, thick green margin. Lower:
tomentum patchy with convex naked areas corresponding to
depressions between the ridges on the upper surface. Note:
scarce in the east, much more common in the west.
AWI Grey thallus of adpressed scallop-like plates with longitudinal
ridges and concentric ‘growth’ rings, felted margins and reddishblackish
fruits. Col: dry = pale grey, sometimes tinged brown; wet =
darker blue-grey. Isid/sored: absent, but sometimes a few knob-like
lobules that resemble isidia. Fr: frequent, reddish; turning blackish.
Lower: thick blackish/greyish velvet mat at edges of upturned lobe
margins (a thick hypothallus). Similar to: see D. atlantica and
Pannaria rubiginosa (in The Lichens of AtlanticWoodlands: Guide 1).
Notes: absent from the east, more common in the west.
AWI A pale thin whitish crust on areas of smooth bark, with
numerous small, very distinctive barnacle-like fruits (x10). Col:
whitish to pale grey. Isid/sored: none. Fr: abundant, like small
barnacles which are the same colour as the thallus. Note: more
common in the west. May also occur on the acidic bark of oak, old
birch and old alder.
British Lichen Society

Introduction
This Plantlife field guide is for anyone interested in
identifying some of the more conspicuous lichens found in
Scottish native pinewoods. It looks at scaly and crustose
lichens that grow on trees with acidic bark and on
deadwood, and at leafy and crustose lichens that grow on
trees and shrubs with less acidic bark such as rowan.
A companion guide (Lichens of Scottish Pinewoods: Guide 1)
looks at the leafy and shrubby lichens found in these habitats.
What are Scottish pinewoods?
They are semi-natural woodlands containing a significant proportion
of Scots pine and often including dead pine. Scots pine and/or birch
may be the dominant tree species, and there is often some rowan,
and more locally, alder and willow. Some pinewoods may also have
aspen, hazel, oak and, especially in the east of Scotland, an
understorey of juniper.
What is a lichen?
A lichen is an association between a fungus and a photosynthetic
partner. The fungus forms the main body of the lichen (the thallus),
usually including a protective, opaque upper surface that can be green,
yellow, orange, reddish, brown, grey, whitish or bluish.The
photosynthetic partner manufactures food using the energy of sunlight
(photosynthesis). In most lichens the photosynthetic partner is a green
alga, but some lichens have a cyanobacterium (blue-green alga).
Mosses and liverworts often grow with lichens. They have green
chlorophyll but no pigmented protective upper surface, and most
species are semi-translucent green or yellowish green, although some
are reddish purple. Unlike lichens, mosses and most liverworts have
a stem with leaves, although some liverworts consist of a thallus that
could be mistaken for a lichen.
Why are lichens of Scottish pinewoods important?
Lichens are important for biodiversity and as indicators of habitat
quality. There are around 1850 species in the British Isles compared
to around 1400 species of native flowering plants. Scottish
pinewoods support a number of specialist pinewood lichens that are
rare or absent elsewhere in Britain.
Most lichens prefer clean air, and require habitats that are not
regularly disturbed. The woods with the most diverse lichen flora
have a varied topography, including river valleys, and a diverse
woodland structure with glades and a range of tree and shrub species
including old trees and shrubs. In areas with historically low levels of
pollution some well-developed pinewood lichen communities may be
good indicators of ancient woodland.
Lichen communities
Distinctive lichen communities in pinewoods include:
The Calicion (the ‘pinheads’): This community is a specialist
community found on very dry bark, bark recesses or deadwood that is
either not exposed to direct rainfall or dries very quickly (e.g. stumps
sheltered from direct rainfall, pine snags and standing pine ‘bones’). It is
typically dominated by thin crustose species, some of which have tiny
stalked fruits that resemble stubble or pinheads under a hand lens.
The Parmelion: In this guide the Parmelion refers to the Parmelion
laevigatae community. It is best developed in the west of Scotland
on trees with very acidic bark such as alder and birch and is absent
from the eastern pinewoods. It is typically dominated by grey, leafy
and crustose lichens including the Smooth Loop Lichen
Hypotrachyna laevigata. The Parmelion community is dealt with more
fully in The Lichens of Atlantic Woodlands: Guide 2 (Acton & Griffith,
2008, Plantlife Scotland).
The Physodion: This is a typical community found on pine bark and
lignum and, in the east and central pinewoods, is very common on
other trees with very acidic bark such as birch and alder. It is
typically dominated by grey and brown leafy lichens, grey crustose
lichens and brown filamentous lichens that look like hair. It can be
very similar to the Parmelion community but in the Physodion
community the brownish Hair lichens (Bryoria species) are generally
much more common.
The Lobarion: The Lobarion can occur on mildly acidic bark but
this community is scarce in eastern pinewoods. It is mainly
associated with old rowan and rain seepage tracks below damaged
bark of old birch but, if present, other tree and shrub species such as
hazel, aspen, willow or old oak can be important. Five species are
described in this guide: Nephroma laevigatum, Degelia plumbea and
three Lobaria species. The Lobarion community is best developed in
Atlantic woodlands and is dealt with more fully in The Lichens of
Atlantic Woodlands: Guide 1 (Acton & Griffith, 2008, Plantlife Scotland).
The Usneion: This community is typically found occurring as
greenish shrubby tufts, especially on branches and twigs in the
canopy. Greenish shrubby lichens (Strap lichens, Oak Moss and
Beard lichens) are frequent on twigs and branches of broadleaved
trees in unpolluted areas. The Beard lichens (Usnea species) are
difficult to identify, often requiring chemical analysis.
Important lichen micro-habitats
The lichens in Scottish pinewoods are associated with several
micro-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 below
damaged areas of old birch.
• Deadwood: Dry, well-lit but sheltered wood without bark
(lignum) is hard and rots slowly. A number of specialist pinewood
species are associated with standing dead pines, leaning or fallen
dead pine trunks and dead limbs still attached to living pines.
Many are tiny specialist species and identification requires
microscopic examination. However, identifying their microhabitats
and the presence of the Calicion (‘pinhead’) community
(by careful searching for tiny lichens that resemble stubble or
pinheads) is relatively easy. In contrast, damp, shaded pine lignum
rots relatively quickly and these habitats (e.g. rotting trunks along
the ground and well rotted stumps) can support a number of
common and widespread lichens (e.g. Cladonia species) that
normally grow on the ground (terricolous lichens). This guide
does not deal with these terricolous species.
Lichen hunting!
This is the fun bit! Arm yourself with a hand lens and explore a
range of woodland habitats, such as old pines (including any ‘granny’
pines, dead standing and fallen pines), tree stumps, old birch, old
rowan, riparian woods and wet woodlands. The occurrence of pale
grey, pale blue-grey to pale green-grey leafy lichens, whitish crusts
and brownish Hair lichens on tree trunks is a good indication of the
presence of the Physodion or Parmelion communities. The upper
canopy will often have a well-developed Usneion community of
shrubby green Beard and Strap lichens. An ancient pinewood will
often have good populations of a range of the species illustrated in
this guide, including some specialist pinewood species that are
ancient woodland indicators (AWI species). Some of the species
described have a restricted distribution (e.g. some are common in
the east of Scotland and absent in the west or vice versa), and some
are quite rare. Happy hunting!
Although common names have been used in this guide, few common
names for lichens are universally accepted. Scientific names should
always be used when recording lichens to avoid ambiguity.
1 CRUSTOSE AND SCALY (SQUAMULOSE) LICHENS on pine, birch and alder
Ochrolechia androgyna A Cudbear Lichen
A thick, warty, whitish or pale grey crust with green soralia;
usually without fruits. Col: whitish to creamy, pale grey to grey
or greenish white. Sored: round to irregular pale green or dull
yellowish soralia that can join to form a continuous crust. Fr:
occasional; pale pinkish to orange-brown disc, thick thalline
margin with soredia. Note: a common species in several lichen
communities on trees with acidic bark and on acidic rocks.
A traditional source of dye. Similar to: when fertile often
mistaken for O. tartarea (no green soredia).
Pertusaria amara Bitter Wart Lichen
A thin to thickish, warty crust with white to pale grey soralia that
taste very bitter (rub with a wet finger and taste!). Col: pale grey,
grey to greenish grey. Sored: soralia white, round, discrete and
scattered or coalescing. Fr: very rare. Similar to: another
common wart lichen, P. albescens (not bitter). Note: both these
wart lichens are common British species in a range of lichen
communities on trees.
Ochrolechia tartarea A Cudbear Lichen
A thick, warty, whitish or pale grey crust with numerous ‘jam tart’
fruits. Col: white, pale grey to grey. Isid/sored: none. Fr:
frequent; dull orange-pink to pale brown disc, thick thalline margin.
Note: A traditional source of dye. Similar to: see O. androgyna.
Mycoblastus sanguinarius Bloody-heart Lichen
A thin to thickish, whitish or pale grey crust with black convex
fruits and often distinctive red ‘blood spots’ where fruits have
dislodged. Col: white, pale grey to grey. Sored: usually none.
Fr: frequent; black convex fruits; scratch one off with a fingernail
to reveal a ‘blood spot’.
Arthonia leucopellaea A Comma Lichen
AWI NS A thin whitish to pinkish crust with abundant irregularly
shaped fruits that appear dark greyish or ‘frosted’ and often appear
to melt away at the edges (x10). Col: whitish to pinkish.
Isid/sored: none. Fr: usually abundant, narrow and irregularly
shaped; blackish disc with a distinctive grey to whitish frosting.
Note: a scarce species that can be locally common in ancient
woodland on old pine, birch, oak. Similar to: other lichens have
fruits that look like Arabic writing on a white background (Graphis
species and other Arthonia species) but thin whitish crusts on old
pine and birch which have distinctive ‘melting’ fruits and a surface
frosting are likely to be this species.
Hypocenomyce scalaris Common Clam Lichen
A crust of tiny matt grey-green to brown overlapping scales like
roof shingles. Lip shaped soredia are found along the upturned
edges of the scales (x10) Col: grey-green, olive- or yellow-brown
to brown. Sored: pale soredia along edges of upturned scales.
Fr: uncommon, blue-black, contorted with whitish frosting, often
with a back rim (x10). Note: a common species on pine
bark/lignum; it can also be common on other trees with acidic
bark, especially in the east. Similar to: H. friesii (no soredia).
Lecanactis abietina Old-wood Lichen
A thin whitish crust (sometimes tinged pinkish) with abundant tiny
stubby, whitish projections on the surface (x10) and/or distinctive
yellow-grey frosted fruits. The photo illustrates a sample with
abundant fruits, some of which have been grazed by invertebrates so
appear black. Col: whitish to pale grey to pinkish. Isid/sored: none,
but the tiny projections with white floury tips (x10) could be
mistaken for isidia or soredia. Fr: common but often found infertile;
frosted yellow-grey. Note: common on dry, sheltered acidic bark
(e.g. pine, birch, oak). Similar to: when infertile similar to other
crustose species but this is the most common thin whitish crust with
abundant stubby whitish projections that occurs on dry acidic bark.
Hypocenomyce friesii A Clam Lichen
AWI NS A crust of tiny shiny grey-green to olive-brown flat or
swollen scales with distinctive, contorted black fruits (x10).
Col: grey-green, olive-brown to brown. Isid/sored: none.
Fr: frequent; often abundant, black, very contorted with a wavy
rim. Note: on pine bark/lignum in old pinewoods. Similar to:
H. scalaris (matt, has soredia). Forms with swollen scales can be
similar to Protoparmelia ochrococca (brown fruits).
Protoparmelia ochrococca Chocolate Rim Lichen
AWI A crust of tiny shiny chestnut brown to greenish-brown globules
(x10). Col: chestnut brown to greenish-brown. Isid/sored: none.
Fr: shiny reddish brown disc with thalline margin. Fruits often
becoming swollen and convex. Note: on pine bark/lignum, birch and
sometimes old alder.
Standing deadwood or ‘Pine Bones’
Deadwood is an important lichen habitat in Scottish pinewoods.
One of the more common species on deadwood, especially in the
east is Xylographa parallela. Deadwood is important for a range of
specialist pinewood species such as Pinhead or Stubble lichens.
Specialist pinewood Pinhead species may occur on pines, pine
lignum and dry, sheltered old bark (e.g. birch and oak). Typical
species include Calicium glaucellum and the Brown-head Stubble
Lichen Chaenotheca brunneola.
Chrysothrix flavovirens Yellow Pine Dust Lichen
Forms large streaks of yellowish powder (like pollen) on
sheltered pine bark/lignum Col: dull to bright yellow-green.
Sored: thallus entirely composed of soredia. Fr: rare.
Note: a number of other yellow powdery lichens occur on
broadleaved trees but large yellow powdery streaks on pine
bark/lignum are most likely to be this species.
Xylographa parallela Woodscript Lichen
A very thin almost invisible crust on deadwood with tiny black
fleck-like fruits (x10). Col: the thallus is often immersed in the
wood and not apparent or only evident as a pale stain.
Isid/sored: none. Fr: abundant, black, fleck-like along the grain
of the wood. Note: a common species on pine lignum,
especially in the east. Similar to: other script lichens but most
woodland script lichens grow on bark rather than wood.