Lichens Get Top Billing

Lichens Get Top Billing

Chester Garden Club members were treated to a fascinating glimpse into one of nature’s less-heralded wonders during Frances Anderson’s recent presentation entitled “The Mystery of Lichens”, illustrated with her many detailed images of Nova Scotia lichens.

Cladonia cristatella lichens
Cladonia cristatella

The image above is a much magnified image of a tiny lichen. Known in the vernacular as British Soldiers, it is common in Nova Scotia.  As a lichenologist and Research Associate at the Nova Scotia Museum,  Frances has studied hundreds of the more than 1000 lichen species in our province.

Frances Anderson, lichenologist
Frances Anderson, lichenologist
Hypogymnia physodes, otherwise known as Hooded tube lichen

Lichens are found in every part of the globe, including deserts and Antarctica. Researchers have estimated the global population of lichens to be in the range of 13,500 to 17,000 species.

Lobaria-pulmonaria, commonly known as lungwort lichen

To the lay person, perhaps the most mysterious aspect of lichens is the fact that although they are part of the fungi order, they are products of a symbiotic relationship between fungi and algae. Frances discussed the various structures in which the fungi provide external features that shelter the algae inside the external layer. Those relationships are species specific.

Cladonia chlorophaea
Cladonia chlorophaea, also known as Pixie cups, established in the cavity of a decaying tree.

Lichens are found on trees, rocks, soil, and rotting wood.  Frances was particularly clear in explaining that lichens do not feed on their hosts but take their nourishment solely from sunlight and moisture. They reproduce either by releasing spores that travel out looking for algae, or by the accidental breaking off of a spur that contains the necessary elements to start a new growth.

Lichen Xanthoria
Golden-hued Xanthoria parietina, sometimes called Sunburst lichen,  adds a splash of colour to an old stone gate-post in Chester.

One of the most common lichens in the Chester area is the grey-green wispy collection of strands known as Old Man’s Beard.

Lichen Usnea trichodea

Lichens grow very slowly, some as little as 2 mm per year. They need moisture to thrive and, when conditions are too dry, they simply stop feeding. Their appearance doesn’t vary through all the seasons of the year.

Parmelia sulcata
Parmelia sulcata, commonly known as Hammered shield lichen

Frances noted that, despite being overlooked by many people, lichens have many uses. They shelter tiny insects at the bottom of the food chain. They also provide nesting material for many birds and for Northen flying squirrels.  Some species even act as pollution monitors.

4 More lichens

Lichens also contribute to the biomass of the forest by slowly building soil when dust blows over them and collects on their surfaces.  Seeds then lodge in the mass and, gradually as the soil builds, plants grow up on the site.

Parmelia squarrosa
Parmelia squarrosa or Bottlebrush lichen, one of the most common lichens found in the Chester area.
Checking out lichen specimens.
Checking out lichen specimens.

To conclude her intriguing fact-filled presentation, Frances asked the lichenologist’s favourite question:   Are you lichen ’em yet?

[Photo credits: Cladonia cristatella, Lobaria pulmonaria, Evernia mesomorpha – R.T. McMullin;   Cladonia stellaris, Hypogymnia physodes, Melanelixa subaurifera, Parmelia squarrosa, Usnea trichodes – M.C. Pross]

0 Replies to “Lichens Get Top Billing”

  1. It really was an interesting talk by Frances Anderson. I was surprised by the “lifestyle” of lichens and by their beauty. It is necessary to get up close and personal to truly appreciate them. There was a great deal of information presented, so I was grateful to see your report of Frances’ talk.

  2. It was fascinating presentation and I will never be able to ignore lichens, wherever they are living.

  3. Good Morning, Loved the presentation on Mon and have enjoyed all over again with this blog. Thanks to the Blogers! Jane

    1. Thanks. Many of our members take a keen interest in ecological and conservation issues so, occasionally, we try to widen the scope beyond basic gardening issues.

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