I have perused Kephart’s Camping and Woodcraft many times, but somehow or other had consistently overlooked his entry on lungwort bread (vol. 1, pp. 324-325):
On the bark of maples, and sometimes of beeches and birches, in the northern woods, there grows a green, broad-leaved lichen variously known as lungwort, liverwort, lung-lichen, and lung-moss, which is an excellent substitute for yeast. This is an altogether different growth from the plants commonly called lungwort and liverwort — I believe its scientific name is ‘Sticta pulmonacea.’ This lichen as partly made up of fungus, which does the business of raising dough. Gather a little of it and steep it over night in lukewarm water, set near the embers, but not near enough to get overheated. In the morning, pour off the infusion and mix it with enough flour to make a batter, beating it up with a spoon. Place this “sponge” in a warm can or pail, cover with a cloth, and set it near the fire to work. By evening it will have risen. Leaven your dough with this (saving some of the sponge for a future baking). Let the bread rise before the fire that night, and by morning it will be ready to bake. It takes but little of the original sponge to leaven a large mass of dough (but see that it never freezes), and it can be kept good for months.”
Last week, my wife harvested a patch of lungwort from the trunk of a white oak tree on the ridge above our place. The resulting bread had a pleasant tea-like aroma and flavor that I liked a lot. So, I requested more for the holiday.
Lungwort, presently classified as ‘Lobaria pulmonaria,’ is actually more prevalent on oak. It resembles liverwort but grows in drier conditions. It is bright green under moist conditions but becomes brownish and papery when dry. The leaf-like growth is leathery and lobed. There are patterned ridges and depressions (pits) on the upper surface. The lower surface often displays a fine layers of hairs. The pits and ribs of the upper surface become the lumps and ribs of the under surface.
Various online sources indicate that lungwort was used in beer manufacture as a substitute for hops by monasteries in Europe and Siberia. It was reputed to be both darkly bitter and highly intoxicating. The plant yielded a permanent black dye when mixed with indigo. Because the pitted and sectioned leaf patterns resembled the surface of human lungs, the plant was used in the treatment of pulmonary diseases, wheezings and shortness of breath.
Now that Kephart’s recipe has whetted my culinary interest in lungwort, it has also refocused my attention on the plant itself. Look for it the next time you’re walking a woodland trail. The leafy green outreaching lobes form rosettes that glow emerald-like in the gray light of early winter.