Here is another cool lichen genus! The Caloplaca are orange crustose lichens that forms nubbly patches on exposed rocks. They are nitrogen-loving little organisms, so when you spot some you have a good hint that there is high nitrogen present (or so I learned on a hike last month with lichen expert Shelley Bensen). You might see it on rocks where birds like to perch and deposit their nitrogen-rich droppings. Caloplaca also is abundant along roadsides with heavy traffic, where car exhaust spews out nitrogen oxide as well as other pollutants.
Caloplaca is a crustose lichen; if you see a bright orange foliose lichen, then you’re probably looking at Xantharia. Look close, because the “leaves” of Xantharia might be very small; and they might look nubbly also, due to the presence of raised little fruiting bodies.
Dead tree branches often bring lichens with them when they fall to the ground; sometimes a single branch will have many different types of lichen all growing close together. One of my favorites looks like papery lettuce-shaped leaves that are pale aqua-gray on top, and dark beneath. A fringe of eyelash-like hairs decorate the edges of the leaves. This is a genus known as parmotrema; there are well over two dozen species of it in the US, according to the USDA PLANTS database.
I’ve always been entranced with the tiny gardens–lush yet austere–that grow on fallen logs. Ferns, lichens, fungi, tree seedlings and more all fall on stumps and fallen trees. On the edge of a redwood forest is a log hosting a minute forest of lichens. Small, dusty gray-green leaves cling to the wood, while tiny upright spires rise into the sunshine. At the tip of each little trunk is a red dot: a saucy salute to the world, if one looks close enough.
This is lipstick cladonia (Cladonia macilenta), one of my all-time favorite plants. Though of course, being a lichen, it is actually a symbiotic growth of fungi and algae–and not a plant at all. It is found on dead wood, the base of trees, and sometimes on rocks. It grows on every continent in the world (with the possible exception of Antarctica); mainly in temperate to boreal regions.