Cladonia Squamosa

Day 23: Sufficiently variable in form to confuse budding lichenologists, Cladonia squamosa is quite common on the west side of the mountains, most often found on rotting wood. A few points (or lack of them!) are helpful in narrowing down the species, if perhaps not the subspecies. Brown apothecia are uncommon, but if you're lucky, that will give you a starting point as will a dense layer of squamules (scales) on the short, squat podetia (stalks). These squamules dislodge fairly readily and often leave the white medulla exposed. The medulla darkens on exposure, so sometimes the lichen has a brownish tinge. Most diagnostic are the openings at the tips of the podetia (not obvious in this photo). Chemical testing is required to narrow down an identification to subspecies.