Wart Lichen: The Tiny Crusty Character You Might Already Have in Your Garden
Meet Verrucaria glaucovirens, commonly known as wart lichen – a fascinating little organism that’s probably already living quietly in your outdoor spaces without you even noticing! This native North American species belongs to the wonderful world of lichens, those peculiar partnerships between fungi and algae that have been decorating our landscapes for millions of years.
What Exactly Is a Lichen?
Before we dive into the specifics of wart lichen, let’s clear up what a lichen actually is. Despite what many people think, lichens aren’t plants at all! They’re actually a remarkable partnership between a fungus and an alga (or sometimes cyanobacteria). The fungus provides structure and protection, while the alga photosynthesizes to create food for both partners. It’s like nature’s ultimate roommate situation that actually works out perfectly!
Wart lichen gets its rather unflattering common name from its warty, bumpy appearance when viewed up close. Don’t let the name put you off though – these little organisms are actually quite remarkable.
Where You’ll Find Wart Lichen
As a North American native, wart lichen has been quietly going about its business across the continent for ages. Like most members of the Verrucaria genus, this species typically makes its home on rocks, concrete, and other hard surfaces where it forms thin, crusty patches.
Is Wart Lichen Good for Your Garden?
Here’s the thing about lichens – you don’t really plant them in the traditional sense, and that’s perfectly fine! Wart lichen and its relatives are actually beneficial to have around for several reasons:
- They’re excellent air quality indicators – lichens are sensitive to pollution, so their presence suggests your local air is relatively clean
- They help break down rock surfaces very slowly, contributing to soil formation over long periods
- They add natural character and a sense of age to stone features, walls, and pathways
- They require absolutely zero maintenance – talk about low-maintenance landscaping!
How to Identify Wart Lichen
Spotting wart lichen takes a bit of detective work since it’s quite small and unassuming. Look for:
- Thin, crusty patches growing directly on rock or concrete surfaces
- A bumpy, warty texture (hence the name!)
- Colors that can range from grayish to greenish, often blending in with the surface it’s growing on
- Very small, almost microscopic fruiting bodies that look like tiny dark dots
You’ll need to get quite close to really appreciate these little organisms – they’re not exactly showy garden stars, but they have their own subtle charm.
Living with Wart Lichen
The beauty of wart lichen is that it asks for nothing from you as a gardener. You can’t really encourage it or discourage it – it’ll show up where conditions suit it and quietly go about its business. If you’re someone who appreciates the natural patina of age on stone features, you’ll probably enjoy having these little colonizers around.
Some gardeners worry that lichens might damage stone or concrete, but the truth is they grow extremely slowly and cause minimal impact to sound structures. In fact, they can actually help protect surfaces from weathering in some cases.
The Bottom Line
Wart lichen isn’t going to win any beauty contests, and you’re not going to find it at your local garden center. But as a native North American organism that quietly contributes to ecosystem health while asking nothing in return, it deserves a bit of respect. If you spot some crusty, warty patches on your stone walls or concrete surfaces, take a moment to appreciate these remarkable little partnerships that have been perfecting their cooperative lifestyle for millions of years.
Sometimes the most interesting garden inhabitants are the ones that choose us, rather than the ones we choose!
