ii: The Chemistry Column
Lessons from lichens Claire Gormley When the calendar changes, I fall into the habit of looking back at the events of the past year. This year, as it was for many, my calendar was filled with cancelled holidays, missed birthdays, and, for the most part, emptiness. The disappointment and grief many of us have felt over 2020 still lingers— an ache made even more poignant for those of us in another lockdown. But as I sat down on my familiar couch (in my all too familiar sweatpants) to research Usnea spp. I was reminded of three important lessons of this lockdown experience: (1) the responsibility we all have to take care of one another; (2) the importance of looking after ourselves; and (3) the duty we have to protect our planet. When I remember these lessons, the year does not feel so empty, and I can look forward to each coming day knowing that I am doing my part. Lichens are unique because they are not a single organism; they are a symbiotic relationship between photobionts and fungus (Cocchietto, Skert and Sava, 2002). The two organisms live together, each contributing to the survival of the other. The photobionts, like algae or cyanobacteria, provide food for both organisms through the process of photosynthesis. Likewise, the fugus provides structural support which protects the algae from drying out, and also water and minerals (Grass, 2017; Cocchietto, Skert and Sava, 2002). These organisms rely on one another to do their part so they both can live, much like our symbiosis with healthcare and other essential
workers. Unlike the lichen, it can be all too easy for us to forget who we are protecting; it goes against our nature to avoid social contact. Yet we have found new ways to connect with those we love, while sustaining the symbiosis. Whether it’s a distanced doorstep dinner with our neighbours, or a zoom happy hour with colleagues, we are playing our part in the relationship so that the other can survive. We have also learned how to truly take care of ourselves. The healing power of a walk in the fresh air was finally recognized when the opportunity to do so was limited. Rest became normalized. Many of us began cooking for ourselves (even beyond banana bread and sourdough) and prioritizing our mental and physical health. Even so, how many of us remain unaware of the expansive roles lichen play in our health? Like plants, lichens produce large numbers of bioactive substances, which provide protection against a range of viral, bacterial, and protozoan parasites, as well as animal predators, plant competitors, and environmental factors like ultraviolet (UV) rays (Cocchietto, Skert and Sava, 2002). One genus of lichen, Usnea, commonly referred to as ‘Old Man’s Beard’ (an obvious name for the scruffy, greyish-green strands), has been utilised by humans for centuries for its properties— sometimes as food, but also as medicine, as witnessed in the ninth century Al-Kindi botanical formulary (Cocchietto, Skert and Sava, 2002). Since WWII, these beard lichens have been the focus of many studies,
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