Usnea Longissima, Mother Nature's Garland

Day 15: For me, the main attraction at Rainey Creek is a tree festooned with Usnea longissima, the lichen I call "Mother Nature's Garland." Its semi-official common name is "Methuselah's Beard," presumably derived from the great lengths it sometimes attains. Unlike other Usneas, it does not form branches off the central cord; it may grow up to 10 feet according to Brodo, but after tracing one strand back a full six, I'm inclined to think that may be a low estimate.

Longissima only thrives where the air is free of pollutants, a factor which may also account for the healthier-than-average population of mosquitoes along Rainey Creek. From the bridge where the Usnea Tree stands, the view shows other trees equally wreathed, but only immediately alongside the stream channel. I have found other wisps of this graceful lichen further from the creek, struggling for survival where they may have been dropped by a bird carrying potential nesting material. This Usnea occurs in other local areas, but to date, I have found none as lush as those along Rainey Creek...as good a reason as any to pay it a visit when the skeeters aren't flying!

Usnea Faerie

Day 42: Look closely, and you may see a Lichen Sprite among the strands of Usnea longissima beside Rainey Creek, an avatar of Nature husbanding her charges with love and kindness. Like the Usneas she shepherds, this faerie is sensitive to air-borne pollutants, and thus as a species, is becoming rarer and rarer in the modern world. Rainey Creek offers the perfect habitat for Usneas and their faerie guardians, but it's best to visit in the autumn or winter. The sprites and visitors alike vie with highly competitive mosquitoes during the spring and summer months.

Comparative Lichenology

Day 41: East meets West for today's essay! A friend recently sent me two lichen specimens from Maine in the hopes that I could identify them for her. One of them was a member of the generic category of "Old Man's Beard lichens," specifically Usnea filipendula (Fishbone Beard, top photos). It put me in mind of my favourite among the Usneas, Methuselah's Beard (U. longissima, lower photos), so I thought it would be fun to present them paired, and thus took a short hike to a location where longissima is abundant.

As you can see, Fishbone is much more compact and delicate. Longissima grows in graceful strands up to ten feet in length. Filipendula branches abundantly, and Methuselah's Beard consists of threads on a central stem, much like a Christmas garland. A microscopic view reveals that isidia (grain-like reproductive units which detach easily from the thallus) are present on both specimens, but are more numerous in the case of filipendula. Both species are excellent air-quality indicators. Sensitive to even small amounts of pollution, Usneas only grow where the air is pure.

On The Subject Of Beards

Day 12: Usneas came up in conversation this morning...yes, I do have friends who talk lichens with me...so I decided to go for a drive and short walk to visit my favourite species, Usnea longissima. Besides being one of the most graceful and beautiful of our local lichens, U. longissima is highly sensitive to pollutants. You can be assured that you're breathing the best air when you find yourself amid trees adorned with its streamers.

This Usnea is largely a lowland species, but that said, it is considered threatened world-wide, and has in fact been extirpated in much of its normal range, over-harvested by collectors selling "moss" to the floral industry. The strands can be up to ten feet long, and the sight of them swaying in the breeze will quickly clue you into how this lichen is transported. They blow on the wind like feathers, the tendrils catching on any available twig, gathering into gauzy curtains of pale green lace. At this site, they seem to have a preference for cottonwood, and occur only on those trees closest to a small stream. I've monitored this location for several years, and am happy to say they seem to be thriving.

Usnea Longissima, Methuselah's Beard Lichen

Day 171: We now resume our regularly scheduled programming, and by that I mean "no more April Fools' jokes."

Frequently and easily mistaken for a moss, Usnea longissima is one of the most elegant members of the lichen family. Also known as Methuselah's Beard, this Usnea grows in strands which may reach lengths of nine feet, and drapes over branches like a tinsel Christmas swag. Like the lung lichens, Usnea longissima is a good indicator of air quality since it is highly sensitive to pollutants. Seen here growing on Red Alder along the Rainey Creek trail, Methuselah's Beard is abundant at the east end of Riffe Lake.