Hammered Shield Lichen

Hammered shield lichen takes its name from its surface texture - a pattern of ridges that resembles hammered metalwork. This common lichen grows on rocks and tree bark across the Northern Hemisphere, producing brown dyes that were historically important for textile coloring (Harris Tweed was traditionally dyed with this lichen).

The lichen demonstrates how common organisms can have outsized cultural and economic impact. It's not rare, not extreme, but ubiquitous and useful. The business parallel is infrastructure so common it becomes invisible - yet entire industries depend on it. Like common lichens dyeing famous textiles, common services often underpin premium products.