Menegazzia On Alnus

Day 161: The Menegazzia species are some of my favourite lichens, partly because they are relatively rare, but largely just because they're cute. Variously known as "tree-flute" or "porthole lichens," they are characterized by round perforations in the lobes as shown in this photograph. There are two species which occur here in the Pacific Northwest, M. terebrata and M. subsimilis. The medulla of subsimilis (above) shows a pink/orange/red reaction when dabbed with Clorox, and indeed the specimen I took from this rosette did react accordingly. Now I did say Menegazzias were "relatively rare." Not so on the South Swofford Trail where, in certain spots, they appear on almost every Alnus trunk in sight. They are particularly attractive (and more noticeable) at this time of year when the centers of its rosettes glow yellowish-green and are bounded by fresher blue-green growth. The lobes are quite small for a foliose lichen, usually under 2 mm in width. Those of M. terebrata are somewhat wider, and of course M. terebrata does not show a C+ reaction.