Stereocaulon Paschale

Day 176: Stereocaulon paschale is one of the "foam" lichens, and a walk through any area where it occurs will serve to justify the common name. It forms large patches which from a distance appear rather like the tidal froth found on ocean beaches. On closer examination, the "foam" resolves into tiny granular outgrowths resembling miniature cauliflower florets sprouting from pinkish stalks. It is often found in areas of old riverbed where stones and boulders have been overgrown with a thin layer of moss, its distinctive dusty blue-grey hue contrasting with brighter greens. Some older field guides refer to it as a subspecies of Stereocaulon tomentosum.

All In A Day's Work

Day 141: These are just a few of the lichen species I documented over a four-mile walk today. All of these are fairly common in the Longmire Stewardship Campground and on the west side of the Park. Top left: Stereocaulon paschale, "Easter Lichen"; top right: Peltigera britannica, "Flaky Freckle Pelt"; bottom left: Platismatia glauca, "Varied Rag" or "Ragbag"; bottom right: Sphaerophorus venerabilis (formerly S. globosus), "Coral Lichen." Each has a special mechanism for capturing and holding precious moisture until it can be absorbed into the lichen's tissues. Stereocaulon utilizes tiny scales (squamules), while both Peltigera and Platismatia have veined, pitted surfaces in which moisture accumulates. Sphaerophorus relies on its lacework of branches to retain even the smallest deposits of dew. Highly adapted organisms, lichens can survive protracted periods of dry weather due to their specialized forms.

Cladonia Squamosa

Day 14: Walking along a short trail in Black Lake Meadows (a small wetland area south of Capitol Mall in Tumwater), I checked up short at the sight of a mound of very scaly little lichens covering a stump of unknown wood no more than a foot high or wide. My first thought was that the lichen was Cladonia bellidiflora, the most squamous of the Cladonias, but on closer observation, I saw that the apothecia were a pinkish-tan colour rather than brilliant red. That feature alone ruled out bellidiflora, so the next fifteen minutes were spent on my knees in the wet grass under light rain trying to obtain a photo from an angle which showed the full morphology of what I believed to be Cladonia squamosa, although I had reservations due to the abundant apothecia.

Updating: I've had one of those "D'uh!" moments. I should have recognized this species immediately because it's quite common in the Pacific Northwest. I'd just never seen it fruiting quite so abundantly. It is Stereocaulon paschale, "Easter Lichen." The remainder of my description has been revised to reflect the corrected identification.

For the uninitiated, "squamous" means "scaly," referring to the pale green shingles on the stalks (podetia) of this species. The apothecia are the fruiting bodies, those little knobs along the upper margins.

Stereocaulon Paschale, Easter Lichen

Day 145: Before you ask, I do not know why Stereocaulon paschale is called "Easter Lichen." It is one of approximately half a dozen "foam" lichens which can be found in the Pacific Northwest, and most of the others have the word "foam" in their common names: Woolly Foam, Rock Foam, Snow Foam. Easter Lichen isn't quite as "foamy" as the others, so perhaps that's why the word was omitted from its nomenclature. The woody, tough stalks of Stereocaulon paschale are often only sparsely covered by the fuzzy tomentum which is a primary characteristic of the family of Stereocaulons, and when this lichen colonizes on soil or mossy rocks, it does so abundantly. This specimen was found on the Kautz Creek trail.