Now that you’ve had some practice finding crustose, foliose, and fruticose lichens, it’s time to fine-tune your observations. Let’s begin with patterns. I urge you to spend some time during the next few weeks learning a few of the most frequently-seen lichen families and familiarizing yourself with their general forms. This post will offer several local examples and two online resources to get you started.
The first resource is the “Explore” tab of iNaturalist. I filtered this page using “Massachusetts” as location and “common lichens” as species, and then selected the “species” tab. This reduces the list of research-grade observations to 177 images. The most commonly observed species are those at the top of the page which indicates that they are either common and/or easily recognizable. My images from Bristol and Plymouth Counties reflect these common species.
For example, this lichen is smooth rock tripe, a familiar sight to hikers of rocky woodlands and an oft-reported species on iNaturalist.
Smooth Rock Tripe, Hingham, MA
It was growing on boulders in Whitney and Thayer Woods, a Trustees property with many glacial erratics. This species belongs to the family Umbilicariaceae. Here’s another species in that group, common toad skin.
Common Toad Skin, Hingham, MA
The similarity is easy to see, if not to put into words. That’s where our second resource helps: the “Morphogroup Index” of the website, Ways of Enlichenment, arranges lichens by groups based on “general form.” While the site includes plenty of detailed taxonomic information, it also uses visual similarities to organize the photos, and then gives the groups pronounceable names. The lichens shown above are included in “The Navels,” a group that is defined as “foliose chlorolichens with a white medulla and a single central point of attachment.” In other words, they are flat and leaf-like; an alga is the photosynthesizing partner; and the lichens are attached at the center. For a beginner, “Navels” is certainly easier to remember than “the Umbilicariaceae.” With repetition, the scientific names will grow on you.
Let’s look at another set of lichens, the beard lichens (genus Usnea). Ways of Enlichenment places these fruticose lichens into a group called “The Hairs.”
Bushy Beard Lichen, Pembroke, MA
This species, bushy beard lichen, is also among iNaturalist’s top ten in Massachusetts. Those hairy discs at the branch tips are called "apothecia" and are involved in reproduction. We’ll focus on anatomy and terminology in a later post.
“The Clads” (for the genus Cladonia) include some spectacular lichens with colorful common names such as British soldiers, reindeer lichens, and pixie cups.
Reindeer Lichen (Cladonia sp.), Pembroke, MA
British Soldiers, Norwell, MA
Some of the most common lichens in Massachusetts are the shield lichens (Family Parmeliaceae) which Ways of Enlichenment calls “The Leafs.” Here’s a specimen growing on a pitch pine in Plymouth. Other shield lichens attach to rock.
Greenshield Lichen, Plymouth, MA
Remember our “What Is It!” specimen from January 6? Lichens with a bright yellow or orange thallus (body) are grouped in “The Flames.” Unlike the previous sets, this grouping is based strictly on color rather than form. It includes species that are very distantly related. The sunburst lichen below is an example from Downeast Maine.
Sunburst Lichen, Cutler, ME
Not far from this rocky beach, tree lungwort grows in a humid, fog-drenched forest. This flamboyant lichen is the creation of three symbiotic organisms: a fungus, an alga, and a cyanobacterium. You will find lichens with this form in “The Mantles” section of Ways of Enlichenment.
Lungwort, Cutler, ME
Although my photos of sunburst and lungwort lichens were taken in Maine, these species also live in coastal Massachusetts.
Just for fun, let’s look at one more lichen, the unmistakable pink earth.
Pink Earth, Pembroke, MA
This species prefers disturbed ground, particularly dry, acidic soil. These were growing near the sand pit of an old cranberry bog. The stalked structures with pink, rounded tops are just what they seem to be: the fruiting bodies of a fungus. In this case, the fungal portion of the lichen will reproduce sexually through spores in these pink "apothecia".
There are, of course, many more lichen species in Massachusetts, and neither of these websites is sufficient for identification. Indeed, Ways of Enlichenment is a site focused on Western North America, though there is some overlap with New England. All the same, I hope these online resources and this post will enhance your ability to see both the diversity and similarities among our local lichens. They are ubiquitous, stationary, long-lived, and fascinating. And, they are easy to observe with a high-quality hand lens. Why not incorporate some lichen watching in your next walk?
Reminder: The deadline for photo submissions for “Picturing Winter” is coming soon. Email firstname.lastname@example.org with your entries by 8 p.m., Tuesday, January 31.
The entries have been impressive. I can’t wait to see yours!
nature blog, the best
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