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Lichens of the Macoun Club Study Area (middle part of list)

////Lichens of the Macoun Club Study Area (middle part of list)
Lichens of the Macoun Club Study Area (middle part of list) 2019-03-24T21:33:15+00:00
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Lichens of the Macoun Field Club’s nature study area in Ottawa, with comments

Dimerella to Placynthiella

Click here to return to the first third of the list: Acarospora to Dermatocarpon and here for the last third: Physconia to Xanthoria

Dimple Lichens Dimerella pineti

(Coenogonium pineti)

Tiny, pale dots on bark. It is a rare old-growth indicator, and we have found it only on the bark and rotting wood of White Cedars where it is most humid, at ground level.
Crater Lichens Diploschistes muscorum A thick, irregular grey crust with sunken discs (like craters). One of our specimens shows the typical features of its life cycle, having started out as a parasite on Cladonia and then grown out over the weathered wood of an old fence rail. We have also found it on the base of a decaying elm tree. It is infrequently encountered in Southern Ontario, and is apparently new to the Ottawa area.
D. scruposus Another thick, bumpy, grey crust producing spores in very small, deep craters, but growing only on stone. The craters have distinctive double walls. We find large patches of this lichen on low, non-calcareous boulders. It is very common in the Ottawa region.
Stipple Lichens EndocarpĀ pusillum (may actually be E. pallidulum) An inconspicuous squamulose (or scale-like) lichen growing on rock, brown when dry, green when wet. It is common in southern Ontario, but is considered rare in the Ottawa region. We have found it on a limestone boulder in a shady deciduous forest, and also on a piece of limestone almost hidden in the dry grass of an overgrown field.
Genus Eopyrenula Eopyrenula intermedia A crustose lichen. Specimen found on Red Maple in a moist forest. Newly noticed in southern Ontario.
Oakmoss Lichens Evernia mesomorpha A rather flabby “shrubby” lichen, with irregularly formed, pale greenish branches. It grows out from tree trunks and branches, and although common, we have found it only a few times in our Study Area, usually on conifers, but twice on the fallen crowns of big deciduous trees in the forest.
Greenshield Lichens Flavoparmelia caperata A medium-large foliose lichen that forms large, distinctively yellow-green patches on tree trunks. It is very common across southern Ontario, but is absent from cities, because it is so sensitive to air pollution.
Speckled Greenshield Lichens Flavopunctelia flavientor A medium large, yellowish green foliose lichen on bark, with lots of tiny white spots and roughened patches of soredia on the lobe surface. We found it on White Cedars that were drowned by beaver activity 30 years ago. It is common in southern Ontario.
F. soredica Formerly known as Parmelia ulophyllodes. A yellow-green foliose lichen very much like F. flavientor but with almost no white spots, and with the soredia only on the lobe margins. It grows on bark (our best specimen is from a Saskatoonberry trunk). Rare in southern Ontario.
Script Lichens Graphis scripta This lichen grows within the bark of trees, often forming large, pale grey patches much marked with short black lines, like some ancient script. It is abundant.
Fringe Lichens Heterodermia speciosa A small, pale grey foliose lichen with large, crescent-shaped soralia on raised lobe tips. It also has (relatively large) white marginal cilia, and dense, curly rhizines underneath. We have found it once on an Eastern White Cedar in the big cedar swamp. It is infrequent in both southern Ontario and the Ottawa region.
Clam Lichens Hypocenomyce scalaris Formerly Lecidea scalaris. A yellowish-green lichen growing as tiny down-turned brackets on trees and bare wood. We find it in the crevices of the bark on very large White Pines. It is very common across southern Ontario.
Tube Lichens Hypogymnia physodes A very common grey lichen with inflated lobes that stick out from the sides of dead conifer twigs. We found a very little bit in the crown of a tall Basswood in the forest.
Starburst Lichens Imshaugia aleurites A small, white foliose lichen, roughened in the central portion with minute cylindrical isidia. We found it on the weathered wood of a stump charred in the fire of 1870. It is frequent across southern Ontario.
Watercolor Lichens Ionaspis alba A faintly brownish crust on a sandstone boulder in a maple forest. The pale fruiting bodies, each about 0.5 mm across, are sunken into the smooth thallus. It is new to Ottawa and southern Ontario.
White Stain “lichen” Julella fallaciosa A smooth, white stain on Sugar Maple trees, speckled with minute black dots. Inside a volcano-like structure are multicelled (‘muriform’) spores. It is infrequent in the Ottawa area, but often whitens whole tree trunks.
Rim-lichens (genus Lecania) Lecania croatica Specimens found on Black Ash and Basswood trees in a moist forest. Newly noticed in southern Ontario.
L. cyrtella Tiny pale brown dots with greenish rims, crowded together on tree bark, especially where it is flooded each year. It is frequent in the Ottawa area.
L. fuscella A crustose lichen on the smooth bark of Basswoods and poplars. There is little to see from the outside except clusters of dull blackish-brown dots, each less than a millimeter wide, but in cross-section the internal structure is apparent. It is new to southern Ontario.
Rim-lichens (genus Lecanora) Lecanora allophana Dark reddish-brown disks with thick, wavy, white rims, on a white crust. Grows on tree bark (we found it on a Sugar Maple). Infrequent in the Ottawa region, but rare in southern Ontario.
L. dispersa

(Myriolecis dispersa)

Tiny brown disks with thick, white rims. The rest of the lichen grows inside the rock (limestone).
L. glabrata Reddish brown disks with thin, white margins on a whitish crust. A common lichen, we have noticed small patches of it on both Philippe’s and Joshua’s Sugar Maples.
L. hagenii

(Myriolecis hagenii)

Our specimen is very small. There are just a few tiny greyish disks with rims, at most 0.5 mm across, with a little bit of lichen tissue around them. It was on a patch of rough bark on a White Birch tree in brushy, mixed woods. The species is common in southern Ontario, but rare in the Ottawa district.
L. hybocarpa We have found the “Bumpy Rim Lichen” on the bark of a small White Ash tree in the open, and on the weathered wood of long-drowned Red Maples in and around a beaver pond. Common in southern Ontario.
L. impudens A whitish crust with small patches of powdery soredia. Fruiting bodies are rare, but occur on our specimen. It is common on roadside trees in southern Ontario. We found it on an old Butternut tree at the edge of a forest.
L. muralis

(Protoparmeliopsis muralis)

A pale, yellowish-green crust with lobed margins, often crowded with pale brown disks in the center. It grows on bedrock in open areas, and is common in southern Ontario.
L. polytropa Pale, yellowish-green dots on granite; the rest of the lichen grows into the rock. Frequent in the Ottawa region.
L. sambuci

(Myriolecis sambuci)

Very small, dark brown disks with grey rims, on poplar bark. The disks are heavily frosted when young. This is an unusual species in that it can have double or even quadruple (16 or 32) the normal number of spores in each spore sac. It is known from the Quebec side of the Ottawa region, but has not been found in southern Ontario before. We find it in the crowns of poplar and Basswood trees that fall in the forest.
L. symmicta Yellow, sometimes waxy looking disks often without rims, on a pale greenish, granular crust that can otherwise look very like Arthonia caesia. Common on tree trunks in southern Ontario.
L. thysanophora Forms pale greenish, dusty-looking spots on Sugar Maple bark, each with a distinctive whitish, fibrous margin (the outward-reaching hyphae of the lichen’s fungal component. Very common in the Ottawa area, but outside of the cedar swamp, where it is frequent, we have noticed it only twice (once on Red Maple).
Lecanora sp. no. 2, sensu Brodo 1981* Probably an undescribed species of Bellemerea, which is othewise an arctic-alpine genus. It looks like an Aspicilia but the apothecia are reddish brown, instead of black. We found it on non-calcareous sandstone.
Disk Lichens (genus Lecidella) Lecidella stigmatea Prominent black disks up to 1 mm across, on a bumpy grey crust over rock. It is very common in southern Ontario.

In cross section, the black dots are seen to have only a very dark green surface. Inside, clear spores sacs each contain eight elliptical spores, themselves just 16 microns long.

Dust Lichens Lepraria eburnea Specimens found on Eastern White Cedar and on a Balsam Fir stump in a moist forest.
Dust Lichens Lepraria caesiella Specimen found on an Eastern White Cedar in a moist forest. Newly identified in southern Ontario.
L. elobata Specimens found on a rock and a poplar stump in a moist forest. Newly identified in southern Ontario.
L. finkii Specimen found on a rock in a moist forest. Very common in eastern North America.
L. lobificans Forms very large, pale greenish patches like dust, or paint, where the air is moist at the base of shaded tree trunks. Common.
L. neglecta A thick, granular grey crust over granite in sunny places. It often forms small, concentric rings on rock, hence the old name, Lepraria zonata We have found it on small boulders and on noncalcareous sandstone bedrock. It is common in southern Ontario.
Lobed Dust Lichens Leproloma membranaceum Forms a thick, apparently dust-like but actually somewhat coherent, pale greenish crust over shady, humid rock walls. It is cottony white inside, and has lobed edges that sometimes lift a little. Rare in Ottawa and southern Ontario, but we think we have found it a number of times.
Jellyskin Lichens Leptogium cyanescens A bluish-grey foliose lichen with 1/8-inch (3 mm-) wide lobes that are roughened by crowds of minute finger-like growths (isidia). It normally does not bear the reddish brown disks seen on other jellyskin lichens. This is a common species in southern Ontario, growing on shaded boulders and tree bases.
L. dactylinum A small, grey lichen with isidia, and also reddish-brown disks on the lobe surfaces. It grows on limestone boulders. It is considered quite rare in Canada (having been found only twice before), but may be overlooked becuase it tends to get lost in the moss also growing on rocks.
L. lichenoides A minutely frilly lichen that tends to be brownish rather than grey. It is common in southern Ontario, and although small, often covers relatively large areas of limestone.
L. rivulare A globally rare species that has a strong presence in a special habitat in our Study Area. It is restricted to tree bases (and sometimes rocks) that are flooded every spring, but later dry out. Its small (1 or 2 mm wide), smooth grey lobes are usually abundantly covered with tiny reddish brown disks.
L. subtile A minute lichen with tiny globose fruiting bodies sitting on rosettes of finely divided grey lobes. We found a large patch of it on the base of an ash tree in a seasonally flooded swamp. It occurs from Mexico to Greenland, but has rarely been found. Our specimen is new to Ontario and the Ottawa district.
L. tenuissimum A minutely frilly, lead-grey lichen that grows among mosses on seasonally flooded tree bases in our Study Area. It had not been seen in southern Ontario since John Macoun found it more than a hundred years ago, until we discovered it on several widely separated trees in our Study Area.
Camouflage Lichens Melanelia exasperatula

(Melanohalea exasperatula)

An olive-coloured foliose lichen, with shiny lobes soon densely covered with minute projections (isidia). We found it on the very fine, dead twigs of a Balsam Fir tree. It has been reported only once before in southern Ontario.
M. subaurifera

(Melanelixia subaurifera)

A very common, brownish-olive coloured lichen whose lobes are tightly pressed to the bark of tree trunks and branches. The surface becomes roughened with soredia that are easily rubbed off, leaving yellowish patches.
Dot Lichens (genus Micarea) Micarea erratica

(Leimonis erratica)

(Formerly Lecidea erratica.) Tiny, shiny black dots (less than 0.5 mm wide) on a greenish background, growing on a noncalcareous rock. In microscopic cross section, small spore sacs are seen to contain eight single-celled spores. The species is frequent in southern Ontario, especially on pebbles.
M. melaena Tiny black dots on an inconspicous greenish crust. It grows on old, rather rotted wood. We found it on the the weathered wood of a pine stump that was uprooted and partly burned in the great fire of 1870. It is infrequent in southern Ontario.

In cross section, the blackness of the dots is revealed as very dark blue-green, with purple highlights. Inside, clear spore sacs are filled with narrow spores, each with two to four cells. The spores are 12 to 20 microns long.

M. peliocarpa Tiny, pale gray-brown globules on a granular green crust, with no rims. We have found it on old, charred stumps and a rotting log in the southern cedar swamp. It is frequent in southern Ontario.
M. prasina A very dark green, granular crust on rotted wood, with many dark, dull brown dots. We found it on a sliver of decayed wood at the base of a White Cedar tree, in a mixed forest. It is rare in southern Ontario.
Dot Lichens (genus Mycobilimbia) Mycobilimbia sp. Our specimen, of minute brown dots directly on limestone, comes from below an overhanging rock in a deciduous forest.
M. epixanthoides A crustose lichen; specimen found on Eastern White Cedar in a moist forest.
M. sabuloretum (Formerly Bacidia sabuloretum.) Some of the many pale green or grey, diseased-looking patches seen on moss-covered rocks have turned out to be this Dot Lichen. We also have found it on the bare rock (limestone) and on the bases of old White Cedar trees. It is common in southern Ontario.
No English name Mycoblastus fucatus Crustose lichen; specimen found on Eastern White Cedar branch in a moist forest. New to southern Ontario.
Stubble “lichens” (genus Mycocalicium) Mycocalicium subtile This minute fungus does not form a partnership with algae, and is therefore not a lichen.

Many members of the fungal genus Chaenothecopsis look like it. One of its distinguishing features is the shape of the spores, as seen under the microscope at 400x magnification — M. subtile spores are darker brown and sometimes almost pointed at the ends (instead of rounded). It can grow so thickly as to give weathered wood (on which it produces bleached-out splotches) a slightly bristly feel. M. subtile is one of the most commonly encountered of the stubble lichens, but is nonetheless infrequent in southern Ontario.

Axil-bristle Lichens Myelochroa aurulenta A pale greenish foliose lichen, with rather large, rounded lobes. It is common on tree trunks in southern Ontario, and we have noticed it particularly on Butternut trees in the forest.
Kidney Lichens Nephroma bellum A brownish foliose lichen with a smooth surface and large fruiting disks on the undersurface of lobes that lift and turn over. It has not been seen in southern Ontario for fifty years. We have found it on three mossy rocks close together in a deciduous forest, in patches 5, 10 and 30 cm across.
Shield Lichens Ochrolechia arborea A pale whitish, sterile crust with powdery patches of sordia. We have found it on the loose bark of Eastern White Cedars drowned by beaver activity in the early 1970s; also on maple bark in a moist forest. It is common in southern Ontario.
Scribble Lichens Opegrapha varia

(Alyxoria varia)

Tiny, short black streaks scattered over tree bark, with the lichen’s algae living inside the bark. It is rare in southern Ontario.
Red Dimple LIchens Pachyphiale fagicola Tiny reddish orange dots on tree bark. In southern Ontario, known only from the Ottawa region.
Shield Lichens Parmelia saxatilis Rare in southern Ontario.
Shield Lichens Parmelia squarrosa A pale grey lichen very much like Parmelia sulcata, but with crowds of very tiny, cylindrical isidia growing on the surface, instead of soredia. Although it is very common in the Ottawa area, we have only one specimen, which we found halfway up a fallen White Ash tree’s trunk.
P. sulcata A moderately large, pale grey foliose lichen. The lobes are about 1/8 inch (3 mm) wide). It is one of the most abundant lichens in the region, seeming to grow on almost every tree. It can cover tree trunks in the open, but in the forest, it is found only in the crown branches.
Starburst LIchens Paremeliopsis ambigua A small yellowish-green foliose lichen on weathered wood. It is common in northern Ontario, and on the Quebec side of the Ottawa region, but infrequent in southern Ontario.
P. hyperopta Rosettes of pale grey lobes with hemispherical mounds of fine granules, on an old, burned stump in open woods. It is common in northern Ontario, and rare in southern Ontario.
Ruffle Lichens Parmotrema crinitum A pale grey-green foliose lichen, with lots of tiny black hairs (cilia) growing off the lobe margins and from the tips of minute, cylindrical growths called isidia. We found a big patch of it on a twisted old Eastern White Cedar in the big cedar swamp. It is infrequent in sourthern Ontario, and rare in the Ottawa region.
Pelt Lichens Peltigera canina A large foliose lichen that grows over moss on rocks and on the ground. The lobes can be an inch (2.5 cm) wide, and are brownish grey with pale tips on the upper surface, but white below, with prominent veins. Special lobe structures raise reddish brown disks upright, or even turn them upside-down. It is our most common Pelt Lichen.
P. elisabethae A somewhat ruffled-looking Pelt Lichen, with a shiny upper surface and lots of tiny lobes (lobules) around the edges and growing along cracks in the surface. It is common in southern Ontario, but infrequent in the Ottawa area.
P. evansiana A large foliose lichen covered with tiny finger-like projections called isidia. We find it in on mossy rocks in a maple forest. It is common in southern Ontario.
P. lepidophora A small, brown foliose lichen with simple, round lobes. Found twice in our Study Area, on moss over limestone. It is frequent in southern Ontario.
P. leucophlebia A very large foliose lichen (with lobes more than an inch across) that is bright green when wet, and gray when dry. The lichen shown here was damp, but drying around the edges. The surface is freckled with small dark bumps that contain nitrogren-fixing blue-green cyanobacteria (while the rest of the lichen contains green algae). We have found it once on a mossy calcareous boulder in a maple forest, and several times at the bases of trees in a mossy cedar swamp. It is frequent in southern Ontario, but rare in the Ottawa district.
P. neckeri A medium sized brown foliose lichen, differing from most other Pelt Lichens in having black, rather than reddish, fruiting bodies. We frequently see it on tree bases in our cedar and ash swamps. It is common in southern Ontario.
P. ponojensis A large, brown foliose lichen normally growing on the ground or on moss. We have found it on limestone. It is common in southern Ontario.
P. praetextata A large pale or dark brown foliose lichen, often with an abundance of tiny lobules on the edges and along cracks in the surface. We find it on limestone and on rotted wood in the ground. It is common in southern Ontario.
P. rufescens A light brown, foliose lichen with pale lobes (because of a dense fuzz on the surface) and edges that are much ruffled. It grows on the ground, but one of our specimens came from a flat, mossy limestone boulder in an open area. Common in southern Ontario.
Wart Lichens Pertusaria alpina A bumpy, greenish-grey crust on bark, with eight spores in each spore sac. We have found it only once, on a very big American Beech tree, along with P. consocians and Trypethelium virens. It is rare in southern Ontario.
P. amara

(Lepra amara)

A smooth, dark greenish-grey crust with powdery white bumps that conceal the fruiting bodies. This lichen tastes bitter, hence the name, amara. We have found it only once, on an Eastern White Cedar in the big cedar swamp. It is frequent in southern Ontario, and infrequent in the Ottawa area.
P. consocians Another bumpy, greenish-grey crust on bark, distinguished under the microscope by having only two spores in each spore sac. It is considered rare in southern Ontario. We have found it only once, in company with other rare lichens.
P. macounii A smooth-surfaced, pale greenish-grey crust on tree bark. The fruiting bodies are concealed in millimetre-high bumps with dots or dimples on top. Inside are spore sacs that contain two huge, single-celled spores (each up to 200 microns long — big enough to see as a speck). It is considered something of an old-growth indicator, but is nonetheless common in the Ottawa region.
Stubble &quot:lichens” (genus Phaeocalicium) Phaeocalicium curtisii An unlichenized species that is parasitic on Staghorn Sumac. The apothecia are on tiny stalks even shorter than the sumac’s own hairs, on branches where those hairs have recently been lost. It is commonly encountered on sumac in our Study Area.
P. polyporaeum Tiny stalked fruiting bodies growing on the tops of small, leathery bracket fungi (Violet Toothed Polypore) on dead Red Maple trees. It is rare in southern Ontario, and new to the Ottawa region, but we seem to be finding it on about every second dead maple examined.
Shadow Lichens Phaeophyscia adiastola A dull grey foliose lichen on rock, with lobes that are roughened with soredia along the edges. It is very common; indeed, the most common member of its genus growing on rock in southern Ontario.
P. cernohorskyi

(P. hirsuta)

A very small grey, foliose lichen. We have found it in the deciduous forest where we have our study trees, namely on Johnny’s White Ash and John Foster’s Rock Elm, and on an upended block limestone known to us as the “Tombstone”. It is considered common across southern Ontario, but infrequent in the Ottawa region.
P. ciliata A smooth-surfaced, grey foliose lichen. We have seen in on the upper trunk of a fallen Basswood tree. Rare in southern Ontario.
P. decolor A very dark grey foliose lichen (with lobes < 0.5 mm wide) on rock. Its upper surface is quite smooth. We found it in the old railway rock cut. Under the name Phaeophyscia endococcina it is considered rare in southern Ontario.
P. orbicularis A somewhat larger dark grey foliose lichen. Rough patches (soredia) occur on the upper surface of the lobes, which are a milliimetre or more across. It turned up in the crown of Diane’s 70-foot tall Aspen tree, which fell down in 2006. Common in southern Ontario.
P. pusilloides The Pom-pom Lichen. A small, grey foliose lichen with many prominent puffs of soredia. We found it on a Butternut limb along an old stone wall. Common in southern Ontario.
P. rubropulchra A small, usually dark greenish grey, foliose lichen with a reddish orange interior that is often exposed by little things that eat lichens. It is the most common lichen on deciduous tree trunks in our forests.
P. sciastra An inconspicous, dark foliose lichen commonly growing on limestone rocks in our Study Area. It is common in southern Ontario.
Whitewash Lichens Phlyctis argena A whitish crust with very small bumps, many of which break open into pale greenish granules. Identification is by chemical reaction — none to chlorine, but yellow changing to red with KOH (potassium hydroxide). It grows on tree bark. We have found it in the crown of a Balsam Poplar, and on the trunk of a Red Oak. Rare in the Ottawa region, and infrequent across southern Ontario.
P. speirea Found on Easter White Cedar branch in a moist forest. Newly identified in southern Ontario.
Rosette Lichens Physcia adscendens A grey foliose lichen with lobes that lift away from the surface and expand to form hood-like structures at the tip. Long white hairs grow from the lobe tips, too. It is one of the most common lichens of roadside trees in southern Ontario, but it is absent from most of our Study Area, which is forest.
Ph. aipolia A tough, whitish grey foliose lichen minutely dotted with white. It grows on trees and their branches where the sun shines on them. We never see it on tree trunks in the forest.
Ph. caesia An almost white foliose lichen that is easily seen on limestone boulders in our Study Area, usually in the sun, but sometimes in forest. It is infrequent in the Ottawa region.
P. dubia A pale grey foliose lichen with narrow (no more than 1 mm wide), branching lobes, growing on flat sandstone bedrock in the south end of our Study Area. It is common in southern Ontario.
Ph. millegrana A minutely lobed, grey foliose lichen that is abundant on tree trunks, whether in the sun or in the forest. It is one of the most common lichens in southern Ontario.
Ph. phaea This lichen looks just like the bark-dwelling Physcia aipolia, except that the apothecia are dark brown to black, never frosted. It also differs in that it is found only on silica-based rocks — in our case, sandstone. It is infrequent in southern Ontario.
Ph. stellaris A lichen very much like Physcia aipolia. It is common in southern Ontario.
Ph. subtilis

(likely Ph. thomsoniana)

A pale grey lichen with rather long, narrow lobes (0.5 mm wide). It grows thickly on silica-based rocks; we have found it on large sandstone boulders. It is infrequent in southern Ontario.
Cryptic Rosette Lichens Physciella chloantha A grey, foliose lichen with prominent rough patches (soredia) on the margins and lobe tips. We have found it three times in the same forest, covering the lower part of big, old Sugar Maples (Gabriel’s [formerly Scott Nelms’] tree, and John Foster’s), and once on the upright block of limestone we call the “tombstone”. It is rare in southern Ontario.

Click here to return to the first third of the list: Acarospora to Dermatocarpon, and here for the last third: Physconia to Xanthoria


Return to Study Area introduction

All photos donated or provided by members and leaders, past and present. Created June 2002 by Macoun Club leader Robert E. Lee. Additions and new photos occasionally, most recently on Nov. 30, 2010. Coding revised in May and June, 2016. Lichen names revised March 2019.