See Alan Silverside’s Lichen Pages for photos of several lichenicolous fungi.

http://mushroomobserver.org/image/show_image/44755

As I understand it…

Many are unrelated to lichenized fungi, including various ascomycetes (e.g. Skyttea in the Leotiales) and basidiomycetes (e.g. Tremella lethariae that grows on species of Letharia, Biatoropsis usnearum, also in Tremellales maybe, that grows on Usnea species, and Athelia arachnoidea in Polyporales that grows on Physcia aipolia among others) and a number of anamorphs (e.g. Sclerococcum and Intralichen) It seems most are “commensalistic” (parasymbiotic?), but some are weakly to strongly parasitic (e.g. Paranectria on a wide range of hosts), or saprophytic (e.g. Phoma, anomorphic fungi (coelomycetes) on various Physciaceae and Parmeliaceae, that can be “saprophytic on phanerogams”).

Others are highly-reduced relatives of lichenized fungi, e.g. Arthonia farinacea and Rinodina insularis, both of which have lost both their thallus and algae. These are lichens that use (parasitize?) other lichens’ algae, for example, and therefore no longer need their own.

Yet others are more properly termed “lichenicolous lichens” in that they are just lichens that establish on top of other lichens. These will often only be lichenicolous at establishment and very rapidly grow free. So rapidly that it’s unknown in many such cases whether the lichenicolous phase is obligate.

Then there are ones like Epilichen that can themselves be lichenized and even “parasymbiotic”. (Although the one species known from the southwest, E.stellatus, growing on Lecidea tessellata, is nonlichenized and parasitic.)

And my favorite, species of Dactylospora, such as D. pleiosperma that grows only on Lecanora caesiorubella ssp. merrillii (commensalistically), that look almost identical to Buellia even in microscopic details, so that if one happens to be growing on a sterile crustose lichen, the apothecia of the parasite are readily mistaken for the host’s apothecia!

There seem to be a several lichen equivalents to Hypomyces or rusts that induce abnormal growth or “galls” in the lichen hosts, e.g. Hawskworthiana and Myxophora.

The type I most often see is a very fine webby network of black hyphae growing on the surface of various parmelioid lichens (esp. Xanthoparmelia for whatever reason). I have no idea how one goes about identifying these, or even what their fruiting structures are.

I Hope that helps! :) Lichens are a very complicated world…

[I got most of this information from “Lichen Flora of the Greater Sonoran Desert Region, Volume II”.]

Appreciate your input. I just figure the name from Brodo/Sharnoff book. Good to know that there are other names.

Nash’s magnificent three volume work on the lichens of the Sonoran Desert region offers some perspective on the relative diversity of lichenicolous fungi. It includes 1836 species of lichens in 280 genera, and 135 species of lichenicolous fungi in 57 genera (Nash et al., vol. 3, p. iv).

“lichenicolous fungi: nonlichenized fungi obligately growing on lichens” (from the glossary of Hinds and Hinds, 2007, p.552)

What exactly are lichenicolous fungi? The fungi in lichens? Ones that associate with lichens that already have their own fungal component, and are less tightly associated with them than their components are with each other?

I uploaded Esslinger’s monster checklist of lichens and lichenicolous fungi for North America into MO’s database. If Esslinger says Acarospora contigua is the same as A. schleicheri (which I’ve never even heard of!) then there is probably very convincing research somewhere demonstrating it is so. Not sure where it is, but…

I though it’s Acarospora contigua but MO list it as depriciated name and proposed another option…