Natural History Photographs

Parasitism is a form of symbiosis in which one partner benefits from the other, while the other is negatively affected. We call the negatively affected organism the host, and the benefitting species the parasite. Below are a few examples from fungi that parasitize on lichens; such fungi are called lichenicolous fungi.
Allantoparmelia alpicola
English:Rock grubs
Veggli (Buskerud), Norway; 1 August 2016. Unknown parasite on Allantoparmelia alpicola.
Arthonia varians & Lecanora rupicola
Bjärby (Öland), Sweden; 14 June 2016.
Arthonia varians parasitizes the apothecia of the host, Lecanora rupicola.
Arthrorhaphis grisea & Baeomyces rufus
Aekingerzand, the Netherlands; 30 November 2013.
Baeomyces rufus is the host, Arthrorhaphis grisea the parasite.
Athallia nesodes
Bjärby (Öland), Sweden; 27 April 2015.
Athallia nesodes parasitically growing on an unidentified species.
Diploschistes muscorum & Cladonia spec.
English:Moss lichen
Baarn, the Netherlands; 25 January 2015.

Diploschistes muscorum growing parasitically on Cladonia spec. After
the host dies, the parasite functions as an independently growing lichen.
Sagediopsis spec. &
Pertusaria hemispherica
Rälla (Öland), Sweden; 15 June 2016.
Sagediopsis spec. growing parasitically on Pertusaria hemispherica.
Pseudephebe pubescens
English:Fine rockwool
Deutsch:Gewöhnliche Fadenflechte
Veggli (Buskerud), Norway; 3 August 2016.
Unknown parasite on Pseudephebe pubescens.
Rimularia insularis & Lecanora rupicola
Deutsch:Parasitische Ritzenflechte
Möckelmossen (Öland), Sweden; 12 June 2016.
Rimularia insularis growing parasitically on Lecanora rupicola.