Polycauliona Polycarpa

Day 111: Well, I hit my brakes, heedless of the guy behind me for the split second it took to remember I was on a busy street, whereupon I put my foot back on the gas pedal and pulled into the next parking area. Then I hopped out of the car, camera in hand, to run back to the lichen I'd spotted while driving. Some things simply can't be ignored. But alas, once I got home and ran it through the field guides, the bit I pared off the tree with my thumbnail proved it to be something I'd seen before, although a somewhat older and more developed specimen. That said, it has a new name, and that makes it worth mention: Xanthoria polycarpa is now known as Polycauliona polycarpa, and if you don't feel like a parrot after saying "poly" that many times in succession, I'll be even more surprised. I'd rather hoped it might have turned out to be Xanthoria parietina (which for some odd reason is still placed in Xanthoria), but its lobes are too narrow. A second whoozamawhatsit, strongly sorediate and green with dark brown apothecia liberated from a different tree continues to elude me. As if I didn't have anything else to do with my time...

Xanthoria Polycarpa On My Beat

Day 311: Recently, I gave a talk to a group of Park volunteers which was primarily focused on lichen species. The first half was conducted indoors and a field trip through Longmire Campground was scheduled for the second half. The field-trip hour turned into two and a half as I conducted part of the group through a more extensive exploration as their enthusiasm gave me the opportunity to talk about one of my favourite subjects. With some adaptations, I will be using the same lecture material for a Nisqually Land Trust talk in a few weeks, but since the Pacific Northwest will soon be entering its autumn weather pattern (read, "rain"), I'm planning an indoor "field trip" for the attendees. To that end, I want to gather specimens of a dozen or so of our most common lichen genera to have available for "hands-on," and one species which I most wanted to demonstrate was Xanthoria polycarpa, so showy with its bright orange colour. That presented a small problem: the only place I knew where I could collect a sample without spending a lot of time driving was behind the gate to a closed community where a friend used to live (and no, I don't know any of her former neighbours). I was about to despair of finding it in a more accessible location when lo and behold, there it was, growing on an ancient Oregon Ash beside one of the waypoints for my Land Trust "Forest Succession" talk, right on my very own beat, and I'd never noticed it before. Maybe I'd been too focused on the Poison Hemlock nearby. Funny how a little thing like that can distract you.

Xanthoria Polycarpa

Day 182: Well, fooey. I was in fairly close proximity to Puget Sound yesterday and happened across a dozen or so landscaping trees which were covered in greenish-gold lichen. Xanthoria polycarpa is common in the Pacific Northwest, but a second rarer species (Xanthoria parietina) sometimes occurs in the Willamette-Puget Trough. Knowing this, I decided to pull back into my parking space despite the rain (I'd been pulling out) and have a closer look. You never know, and if you don't check, you might miss something good. Initially, I was impressed with the size of the apothecia on this particular specimen. Then I noticed the size of the lobes. "Hmmmm," sez I. "That's bigger than any polycarpa I ever saw before." I had not brought a hand lens, nor had I brought a container, but I lifted a small sample from the bark and put it in one of the cup-holder slots in the car, reminding myself gently not to put my water bottle back in on top of it. It was the first thing I brought in the house when I got home eight hours later. This morning, I picked off one of the apothecia and did a close inspection under the dissecting scope. Nope, no rhizines at all. Hopes dashed, I was forced to rule out parietina. Drat.

Aptly Named "Sunburst"

Day 19: While a lot of lichens have some rather strange common names (Frog Pelt, Ticker-tape, Volcano, Deflated Tube), the logic behind "Sunburst" is obvious. Its Latin nomenclature reflects its colour and abundant apothecia: Xanthoria polycarpa, i.e., "xanthous" (yellow) and "many-fruited." It occurs farther inland than its cousin X. parietina, a species which in any event is rather rare on the west coast. Look for the apothecial disks which distinguish it from Candelariella vitellina (Common Goldspeck). Sunburst will be found on tree bark, Goldspeck almost always on rock.

Xanthoria Polycarpa, Sunburst Lichen

Day 237: Two very similar species of Xanthoria occur on the west coast of North America. Xanthoria parietina is primarily a coastal species while Xanthoria polycarpa (shown) can be found further inland. The two species can be quite difficult to differentiate when observed in the transition zone.

It is interesting to note that X. parietina is believed to have been introduced from Australia. X. polycarpa is native, and its range extends from central Alaska southward. The taxonomy is derived from the Latin "xanthus," meaning "yellow" and "polycarpus," "many-fruited" (referring to the abundant apothecial disks).

Xanthoria Polycarpa, Sunburst Lichen

Day 176: From the Latin "xanthus" meaning "yellow," the Xanthorias are a very distinctive genus of foliose lichen and, at least in the Pacific Northwest, are most commonly found growing on hardwood bark, generally in sunny, open locations. Xanthorias also colonize on rock. Their colour is striking, and often gives rise to expressions of repugnance in the uninitiated, on the order of, "Ewwww! What's that orange stuff all over the trees?" On closer examination, the structures of the lichen become apparent: a foliose thallus dotted with raised apothecial disks. Xanthoria polycarpa occurs farther inland than the very similar X. parietina, although both are primarily coastal species. X. parietina is not known to occur in Washington.