People ask me all the time if you can eat lichens. For most lichens you *can* eat them, but they just aren't very delicious or particularly nutritious. I think the better question is *should* you eat lichens, and the answer is generally NO. So knowing that, what smart guy decided to start calling the critically endangered O. arizonica potato-chip lichen? Basically BEGGING for it to be eaten? I don't know but please, if you come across this dude and think "mmmm, cronchy . . . " just leave him be, OK? This umbilicate foliose lichen grows on cliff and vertical rock faces at high elevations in SW USA. It can grow up to 20 cm in diameter, but usually can be found in round, folded bunched 5-10 cm across. The upper surface is yellow and ridged, with round papillae surrounding punctiform (dot-like) pseudocyphellae (areas of the cortex lacking algal cells so as to appear paler than the rest of the surface). The lower surface is dark blue-green to black, and covered in more papillate pseudocyphellae and tubercles. It produces lots of apothecia, which have a red-brown disk and prominent margin. O. arizonica has a patchy, unpredictable distribution, and was once likely more widespread according to historical records, but whatever factors have caused its decline are still not understood. Like with so many lichens, more research is needed to fully elucidate its specific niche, and measures should be taken to protect these lil rock snacks until we know more.
