The Winter Solstice! Beginning tomorrow the days will begin to lengthen and before long new growth and color will once again brighten the landscape.
Even in the depths of winter the bright, almost fluorescent yellow-green or chartreuse American wolf lichen (Letharia columbiana) contrasts sharply with the dark colors prevalent during this season.
American wolf lichen is common in western North America, except on the immediate coast, and ranges as far east as the Continental Divide. This lichen is found on the bark and wood of conifers, usually at higher elevations, When growing in profusion it occasionally resembles a pelt covering a tree trunk.
Lichen are organisms involving a symbiotic relationship between fungi and algae. Letharia columbiana is a fruticose (shrubby form as opposed to flat or leafy) branching lichen. L. columbiana has sexual fruiting bodies (apothecia) with brown discs on which the spores are formed. Asexual reproductive structures (isidia and soredia) are not usually found on American wolf lichen.
American wolf lichen contains vulpinic acid, a poisonous yellow pigment. Historically Letharia was used to poison foxes and wolves by mixing the lichen with animal fat or other bait. Native Americans also used American wolf lichen as a pigment.
American wolf lichen displays its brightest coloration when fresh and moist. Often people will collect wolf lichen for horticultural displays or for its brilliant color. However, with time, as wolf lichen dries it becomes brittle and grey green in color – not the stunning specimen that was originally collected.
These American wolf lichens were photographed near Dan Ryan Meadow along Ash Creek (Lassen County CA).