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.