Norstictic Acid Crystals
<p>Scientific Name: <i><a href="https://en.wikipedia.org/wiki/Aspicilia" class="extiw" title="en:Aspicilia">Aspicilia</a> cinerea</i> (L.) Korber
</p><p>Common Name: Cinder Lichen
</p><p>Certainty: positive (<a rel="nofollow" class="external text" href="http://bornnaturalist.org/notes/20080415#7">notes</a>)
</p><p>Location: Canadian Rockies; Wells Gray Provincial Park; Edgewood Blue
</p><p>Date: 2008-04-15
</p><p>This is what happens if you add KOH to an apothecial section while watching under the compound microscope.  Out of seemingly nowhere all these cool red radiating needle-like crystals form.  This is a reaction of the lichen substance norstictic acid with KOH.
</p><p>Macroscopically, if you put a drop of KOH on the nice ashy-white surface, it also turns a very pleasing bright red.  Always amusing, no matter how many times you see it!
</p>
Apparently, the shape of the crystal is diagnostic of the type of acid present.  They will also show up nicely under cross-polarized light, but I'm not set up to get good photos of that yet.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/7147684@N03">Jason Hollinger</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/7147684@N03/2421984969/">Norstictic Acid Crystals</a>