Excerpts from Jim Conrad's
Naturalist Newsletter


from the June 7, 2009 Newsletter, issued from the Siskiyou Mountains west of Grants Pass, Oregon:

On the same boulder down in the moist, sheltered valley where the Broadleaf Stonecrop flowers there's a nice population of lungwort lichen, variously known as Tree Lungwort, Lung Lichen, Lung Moss, Oak Lung and Oak Lungwort. It's LOBARIA PULMONARIA, and you can see part of a large carpet of its human-ear-size flakes plastered across a serpentine boulder's surface above.

This is a fascinating thing. We know that lichens are composite beings comprising two distinct forms a life, a fungus and an alga. However, lungworts, classified as foliose lichens, consist of an ascomycete fungus and an alga living in a symbiotic relationship with a cyanobacterium -- a symbiosis involving members of three KINGDOMS of living things! And the Plant Kingdom isn't included.

In this arrangement the fungus provides structure and handles reproduction; the alga and cyanobacterium photosynthesize food for the lichen, and the cyanobacterium further fixes atmospheric nitrogen for the organism.

Lungworts reproduce both sexually and asexually. I read that sexual reproduction happens when the plant has been established for about 25 years. Then the fungal part of the species produces small discs known as apothecia, which contain asci, from which spores are ejected into the air. You can see a drawing of an apothecium, or "fruiting body," with its asci at http://www.backyardnature.net/f/funclass.htm#a.

The lungworts on the boulder down below must be at least 25 years old because they are producing many apothecia, as you can see in the close-up below:

Lungwort, LOBARIA PULMONARIA, apothecia

The black discs atop the white columns are the asci-containing apothecia. When they first form the discs are reddish-brown but with age they turn black.

Most lungwort reproduction seems to be asexual, however. Frilly edges of the sheets dry up and become brittle, crumble away, and the tiny fragments grow into new plants.

One reason the species bears so many common names is that it's distributed in many rainy places throughout North America, Eurasia and Africa. Back in Mississippi it grows on steep, north-facing, mossy walls of deep gullies in loess -- down in the bayous.

In many cultures lungwort has been used medicinally for lung ailments because the lichen looks like human lung tissue. The Doctrine of Signatures supposes that that if something looks like a part of the body, that's an indication that it's medicinal for that body part. Even though this doctrine is pure superstition, a hot-water extract brewed from it has been shown to have anti-inflammatory and ulcer-preventing activities.

It's also been used to produce an orange dye for wool, to tan leather, in the manufacture of perfumes and as an ingredient in brewing. A couple of times on extended backpacking hikes I've eaten it just to fill my stomach, but it was leathery, had a dank, fungusy taste and I don't think I got much nutrition from it.

You might guess that such a long-lived, complex organism might be having problems surviving. It's true that it's disappeared from certain areas, particularly those with high air pollution and acid rain, and where clearcutting has opened the forest to drying air and sunlight.