Peltigera Venosa, Fan Lichen

Day 248: Peltigera venosa is the smallest Pelt lichen to be found in Mount Rainier National Park. In a mature specimen, individual lobes measure only 10-15 mm. wide with brownish-red lentil-sized apothecia generally visible on the margins. Its most distinguishing feature (apart from being bright green) can be seen on the back side of the lobes; true to its Latin name, P. venosa is heavily veined. Interestingly, unlike many other Peltigeras, venosa's reproductive structures occur on the lower surface of the lobes rather than the top, and when these cephalodia (vegetative propagules) become detached, they usually drop close to the parent lichen. A young P. venosa can be seen on the righthand side of the photo. Peltigera venosa is easily the most recognizable species of Pelt in the Park.

Peltigera Venosa, Fan Lichen

Day 135: Mount Rainier National Park hosts quite a variety of Pelt lichens, but one I had never recorded was Peltigera venosa, commonly called Fan Lichen. This Peltigera is unique among its fellows in that it exhibits distinct, raised veins on the underside rather than the rhizines (root-like structures) typical of the genus. In fact, it attaches to the substrate with a single rhizine at the very base of the lobe. One of the easiest Pelts to identify, its bright green colour fades to a dreary grey-green in dry conditions. I discovered it along Westside Road while looking at something else, ironically only a couple of days after remarking to a friend that I had not seen it in the Park. There were only half a dozen "leaves" of this small species present at this site.