Lichen Spotlight – Vulpicida pinastri

The Powdered Sunshine Lichen or Vulpicida pinastri is certainly one of the most striking of Colorado lichens. For those of us who like to identify lichen to species it also happens to be highly distinctive!

Vulpicida pinastri – Gregory Canyon, Boulder CO

This species is quite common once you know where to look for it. It likes cool wetter areas in the higher areas of the foothills up to timberline. It is a corticolous lichen, fancy scientist speak for growing on trees of bark. The species has a particular fondness for stumps, especially where humans have cut down a tree. Like other species that prefer exposed wood and not bark, it also grows on other human-made substrates like fences.

It can be rather immediately identified by its erect foliose structure, the intense yellow marginal soredia that look like a crust on the outer edges of the lichen, and a blue-green thallus. This species is almost always sterile, meaning the lichen only reproduces asexually by the dispersal of tiny particles of those beautiful yellow soredia.

Vulpicida pinastri on an old stump, a common substrateGregory Canyon, Boulder CO. Click to enlarge.

I tried to find more about the species’ natural history, and like many lichens there is not much out there. It is a Holarctic species distributed in northern hemisphere in both North America and Eurasia. It can be found in boreal forests and at higher elevations in mountains further south. That’s us in Colorado! One study1 used this species to show that some lichen substances are indeed toxic and are a possible way to limit anything from eating them. Another presentation2 made the bold claim that chemicals produced could have potential in the treatment of Alzheimer’s! At any rate surely there is more to learn about this lichen, but for now head up into the mountains and try and spend some time with your new acquaintance Vulpicida pinastri.

1 Pöykkö, H., Hyvärinen, M., & Bačkor, M. (2005). Removal of lichen secondary metabolites affects food choice and survival of lichenivorous moth larvae. Ecology, 86(10), 2623–2632. https://doi.org/10.1890/04-1632

2 Ureña Vacas, I. M., González Burgos, E., & Gómez-Serranillos, M. P. (2019). Antioxidant capacity and cholinesterase inhibitory activity of vulpicida pinastri lichen and its chemical composition. Proceedings of 5th International Electronic Conference on Medicinal Chemistry. https://doi.org/10.3390/ecmc2019-06317

Life Finds a Way

Underpass to the Highway 36 onramp on Baseline Road, Boulder.

You may well be asking why on earth I have started this post with a picture of an underpass, but on a windy day in Boulder here I was.

I have always been fascinated by the life that manages to persist in heavily disturbed urban areas like the plants sprouting through cracks in the sidewalk. While sometimes easy to simply dismiss the life that persists in these places, to wish that native species could be flourishing instead of the non-native weeds, bugs and animals, I think learning what can live in the midst of all of humanity is a worthwhile task. As I set off my soap box I present to you one such organism.

Flavoplaca citrina (tentative) – Growing on a synthetic fiber. See the retaining wall on the left side of the top photo and you can just barely see the black material with yellow crust on top.

I was quite surprised to see large patches of a yellow lichen growing on some material presumably used to help keep the dirt in place on the retaining wall. I was even more surprised when I looked closer and determined it was a species I had clearly never seen before. When attempting to key out this specimen I had no good answer it asked me what substrate it was growing on! If you believe it construction material wasn’t an option. Presuming I have the species correct in Tom Nash’s excellent Lichen Flora of the Greater Sonoran Desert Region. Vol 3 possible substrates for the species are “on wood, bark, bryophytes, non-calcareous or calcareous rocks.” This to me shows that the species can be rather opportunistic when it comes to where it can grow. Perhaps a reason it chose this man-made material as a home.

Next time you are on a walk through the city and you see a splash of color where you don’t expect take a closer look you may just find a lichen adapting to the new urban environment we have created.

Flavoplaca citrina (tentative) – Showing off it’s apothecia (bright orange discs with yellow rims) which were present on some but not all colonies of the lichen.

One of the main reason’s I wanted to start writing on lichens is to show others how to start identifying them. So watch out I’m going to get technical down here and describe this lichen.

Let’s start with a description of the thallus. Step one, it has a thallus, this is the yellow portions in the above photo, and is the main body of the lichen. In some of the small crustose species the entire thallus can be hidden within the substrate and only the apothecia are showing. The thallus also has no distinct leaf-like shapes at the edges (non-lobate) and only consists of little individual specks (areolate).

Second step color, yellow and orange lichens are rather distinctive and, in general, are going to belong to only a few groups of lichens. When presented by a new yellow or orange species a chemical test with Potassium Hydroxide solution is a good step. Lichen aficionados call this a K test. Fun fact K is a product used for some dermatological applications and is super easy to buy. Please inform your spouse before they ask why you purchased foot fungus medicine. I digress. Treat a small section with the reagent and it may well turn blood red. If this is true you have a member of the family Teloschistaceae, as was true today.

Next step is describe the reproductive structures (I hope for a full post about this soon). In the last photo we have apothecia disc or cup shaped structures, but looking closer there is more.

Microscope view of the areoles (the individual units of yellow above). A continuous thallus is not divided this way. See also the marginal soredia.

Looking closer we see powdery masses on the margins, these are soredia. This powder can disperse in the wind or hitch a ride on an animal and if it find the right place to live a new lichen can form. Lichens are weird, as you may have picked up on, this specimen reproduces both sexually (apothecia) and asexually (soredia). Talk about keeping our options open.

Hopefully those that kept reading learned a new term of two. Identifying lichens can be extremely hard, and a good key is necessary, or even specialized equipment. If you think I blundered this ID (very likely) let me know I would love to know why.

An Introduction

Hello! I am very excited to introduce myself. My name is Nick Moore. I am looking forward to sharing the world of Colorado Lichens and I hope to be a regular contributor to this wonderful site that has been built over the years.

So who am I, you might ask. I am someone who has always loved nature, who only recently decided to learn the ways of lichens, and has leapt headfirst into this new world. Hopefully those that stumble across these posts want to come along for the ride.

Why don’t we start with some of my favorite local species. These are some charismatic species that can be found on just about every hike through the lower foothills of Boulder County.

Rusavskia elegans – Anne U White Trail, Boulder CO. On Granite

By far the most common orange lichen on rock along the front range. Older references may refer to this species a Xanthoria elegans.

Pleopsidium flavum – Mount Sanitas, Boulder CO. On Granite

The answer to what’s that yellow on that rock over there along much of the front range. This lichen has an amazing need to be on vertical rock faces.

In a prelude to what I hope will be a future blogpost this species has been taxonomically unsettled in the state. So I would not be surprised to someday learn that this is the wrong name for this lichen or even that multiple species are involved. That day may come as soon as the right person reads this paragraph!

Dimelaena oreina – Mount Sanitas, Boulder CO. On Granite

Perhaps my favorite front range lichen. Once you learn it you will find it very common on sunny exposed rocks. But, unlike the previous species you will find is accompanied by a whole host of similar colored species. Identifying lichens is hard, observing them in all their beauty is easy.

Parmelia sulcata – Button Rock Preserve, Boulder CO

Start walking up your favorite foothill trail. When you get to a nice cool spot under the shade of a big conifer, look down into the tangle of moss and lichen at the roots of the tree. One of the lichens you find is sure to be this wonderful foliose lichen and you’ll soon find it on other substrates as well. Just be sure to note the raised web of white tissue forming what look like cracks (pseudocyphellae) characteristic of the genus. Keep searching and you will find that sulcata is not the only member of the genus present in Colorado.

I hope you enjoyed the post. Perhaps you noted that each photo here links to my iNaturalist observation for the lichen. I hope to have iNaturalist be a constant part of my posts here, and you can always see more of my photos by searching for @nickmoore91. I post everything from birds, insects, fungi and more. Feel free to reach out!

My CO Lichen Observations – Warning some non-lichenized ascomycete fungi show up in that search!