Lobe edges rough with soredia

A medium sized, yellowish green foliose lichen, with long, ribbon-like lobes that are roughened with soredia along the edges. It grows on wood and tree bark in shaded forests. We have found it only once, on an old, burned stump. It is common in southern Ontario.

Tips of fruiting bodies emerge from grey thallus

The tiny black fruiting bodies of this pyreno-lichen (like a volcano) are closely scattered over the outside of tree bark, while the body of the lichen lives inside the outermost, dead layers. Scrape the bark with your fingernail and the lichen’s yellowish green algal partner is visible. We have found it once only, on the bark of a big, old Basswood in our Study-Tree woods. It is rarely seen in southern Ontario, or the Ottawa region.

Close-up of several apothecia

A good many comma lichens appear as clusters of almost flat, irregular blackish marks on tree bark, but this one produces instead fuzzy white bumps. We have found it once, on cedar bark in the big cedar swamp. It is rare in southern Ontario, and new to the Ottawa region.

(Chrysothrix caesia)

Scattering of reddish-brown, frosted lirelli (like elongated, much-branched apothecia)

A smooth gray crust on smooth tree bark, inconspicuously marked with irregular fruiting bodies that are actually dark brown but are also “frosted” and hence greyish. We have found it only once, on the smooth bark of a dead Black Ash in a cedar swamp. It is new to the Ottawa area and southern Ontario.

Septate, needle-like spore

Dark reddish brown dots on bark. Bacidia spores are needle-like, divided into sections by cell walls. This one is 53 microns long. We have found B. polychroa on Black Ash and Basswood trees in wooded swamps. It is common in southern Ontario.

Granular thallus with pink apothecia

We have found this lichen only three times, twice in bark crevices on 130-year-old study trees (White Ash), and once on an even older Eastern White Cedar in the big cedar swamp. The granules that make up the body of the lichen — they are about one-tenth of a millimetre across — are green with algae, while the pinkish disks are the lichen’s fruiting bodies, which contain only fungal hyphae and spores. It is considered rare, and is something of an old-growth indicator species.

Lichen over moss, an inch or two across

There are several Dot Lichens, and this pale greenish one forms diseased-looking patches on moss over rock. The dots are the tiny pinkish fruiting bodies, which can be abundant. It is considered rare in southern Ontario. We have found it twice.

Cross-section of apothecium under the microscope

Tiny black discs (0.25 mm across) with brown, two-celled spores only about half as long as in B. stillingiana, as drawn just below. We have found it with Calicium trabinellum on the weathered wood of a fallen Tamarack in the big cedar swamp. It is new to Ottawa, and rare in southern Ontario.

Hand-drawn cross section of apothecium, with 2 spores enlarged

Large black discs (1 mm) on whitish patches on tree bark. It should be fairly common, but we have found it only three times so far. In cross section, the black colour is seen to be only a surface layer, with columns of dark spores inside. Under high magnification, these are brown and two-celled. Each is about twice the size of a human red blood cell (or about 16 x 7 microns).

Powdery black spore mass at tops of stalks

Stoutly stalked black fruiting bodies, each about 1 mm tall. Note the faint, whitish rim on the cup holding the spore mass. We have found it on a tottering old stump in the big cedar swamp. It is rare in southern Ontario, and new to the Ottawa region.

Waxy apothecia

Tiny, slightly waxy-looking yellow dots on small dark gray patches on smooth Basswood and Balsam Poplar bark.

Orange apothecia crowded over yellowish-grey thallus

A conspicuous yellow-and-orange lichen encrusting limestone rock. Common across southern Ontario.

Grey-rimmed apothecia

Infrequent in the Ottawa area; we found it on a Butternut branch. Yellow dots with whitish margins.

“Candle Lichen” thallus

A very common and readily visible yellowish-green foliose lichen — with very minute features. We usually find it on the bark of any tree examined, whether in the forest or in the open, and occasionally on rock, as shown here, much enlarged.

Abundant apothecia

Bright yellow dots speckled over sandstone or granite, together with tiny, smooth yellow patches of lichen. (The dark areas here are just intense shadow.) Sometimes we have found it on tree bark, too (including poplar and Basswood tops). Very common in southern Ontario.

Stalked apothecia

Tall black stalks (all of 2 mm!) with brown tips, without the white dusting that characterizes Ch. trichialis. The rest of the lichen, the part with the algae, grows inside the bare wood. We have found it once, on the softly rotted wood at the base of a dead Tamarack, deep in the big cedar swamp. It is rare in both the Ottawa area and southern Ontario.

Bright, lumpy thallus with stalked apothecia

Clusters of intensely yellow or greenish yellow bumps, with black-stalked fruiting bodies that are also yellow at the top. Our specimen, shown at right, came from the bare, dry wood of a dead Tamarack in the big cedar swamp. It is new to southern Ontario.

Powdery green thallus with stalked apothecium

A powdery greenish lichen with slenderly stalked fruiting bodies. The cup that holds the spore mass is light brownish white. Our specimen comes from the bark of an old cedar tree that is just barely alive, down in the big cedar swamp. It has been found on the Quebec side the Ottawa River, but is new to southern Ontario.

From the 1970s through the 1990s, acres of dry ground (the “pine barrens”) were covered with Reindeer Lichen mixed in with very low blueberry bushes, but after 2000, these lichens almost disappeared from the place. They do, however, turn up anew under acidic Red Pine plantations.

Cladonia chlorophaea and C. pyxidata are very common pyxie-cup lichens; C. phyllophora is a little less so. C. floerkeana  (Gritty British Soldiers) is a more southerly species that was new to southern Ontario when we found it, but all the Cladonias at that site are being ground out of existence by the trampling of hikers. C. cristatella (British Soldiers) and C. macilenta (Lipstick Powderhorn), which also have red apothecia at the top of slender stalks, are much more common lichens.

C. subfurvum

Close-up of thallus and apothecia

This is one of the few species of Cyphelium that is conspicuous and bright greenish yellow, with a scattering of black dots. We have found it several times on isolated conifer stumps around the ponds.

Brown lichen turns green when wet

Tan coloured, leathery lichens when dry (like D. miniatum, immediately below), but which turn bright green when wetted, as shown at right. It is common on rocky streambeds and lakeshores in the Ottawa area. We found a single large thallus (4 inches across) on a granite boulder in a vernal pond.

Small, circular, leathery lichens on limestone. We have found it only once, on a boulder in a maple forest. It is infrequent in the Ottawa area.