Spring is brief in Colorado, making it very important to play hooky this time of year! This post records an adventure from back in May 2009, a wetter spring than Colorado has had in recent years. That made it a perfect time to visit Lair o’ the Bear Park with a friend to see jelly lichens.
I hadn’t visited for a while, so had to check every cliff to find the right one, way out at the west end of the creekside trail that was once the main road from Morrison to Evergreen, shortly before it enters adjacent Corwina Park.
Eventually we reached the proper cliff, where we could see not only the sought-after jelly lichens, but the wonderful Sticta, and verdant masses of spikemoss, Selaginella. The jelly lichens were soft and slimy from recent rains and lingering rivulets in the cracks and crevices of the cliff. In this photo, a large Umbilicaria (lichen, not a jelly one) is under the ring, with dark Selaginella to its right, and lighter-colored masses of true mosses surrounding.
Properly called gelatinous lichens, these lichens are so named because they lack the firm texture of more typical foliose lichens and have a characteristic translucence when wet. (They remind me of the “tree ears” we sometimes encounter in Chinese restaurant dishes, but those are actual fungi.) Gelatinous lichens are unstratified or only partially so, lacking the distinct algal layer, and sometimes the firm lower and/or upper cortex found in the “typical” lichen (if there is such a thing). The primary phycobiont species is a cyanobacterium, generally Nostoc.
They look so different when they’re dry! This one is, I believe, a species of Leptogium, with a white tomentum visible on the lower surface. Perhaps L. saturninum, but confirmation will have to await another trip. With a hand lens. For those who prefer common names, LoNA* calls this one bearded jellyskin.** (Ugh!)
By the way, you can sometimes find free-living forms of terrestrial Nostoc in Colorado (more commonly here in NY). We’ve seen them on Lyons Sandstone near Red Rocks Park.
* LoNA is Lichens of North America, the coffee table book of lichens, by Brodo, Sharnoff, and Sharnoff. Highly recommended! You can see Sharnoff’s species photos from the book at Sharnoff Lichen pages.
** Jellyskin is the name used here for the entire genus of Leptogium, as opposed to the name “jelly lichen” given only, in that book, to species of Collema, another common jelly lichen. This is the only book I know that assigns common names to lichens; few lichens have true common names.