Verrucula
Verrucula is a genus of lichenicolous lichens in the family Verrucariaceae. Species in the genus are parasitic on saxicolous, crustose lichens, including Xanthoria elegans as well as lichens from genus Caloplaca that contain chemical substances called anthraquinones.
Taxonomy
Verrucula was originally circumscribed in 1896 by Austrian lichenologist Julius Steiner to contain a group of parasitic Verrucaria species. It was subsequently little used until 2007, when it was resurrected for use for Verrucaria found as parasites on Caloplaca with anthraquinone compounds. Other parasitic species were moved to genus Verruculopsis; these two genera are morphologically quite similar. Molecular phylogenetic analysis shows that Verrucula has a sister taxon relationship with Placocarpus in the family Verrucariaceae.Description
Verrucula lichens have a thallus that is areolate to a mixture of squamulose and areolate, and is sometimes reduced in form. The upper cortex is only weakly developed, and is termed a pseudocortex. The excipulum is pale except for the pale to pale brown area around the ostiole. Ascospores are colorless, and usually simple, although in rare instances they have a single septum. Pycnidia in Verrucula are similar in form to those found in genus Dermatocarpon. This is pycnidial type is characterised by its paraplectenchymatous net and its multiple cavities.Species
, Species Fungorum accepts 16 species of Verrucula. The following list gives the species name, author citation, year of publication, and host lichen. The host specificity in genus Verrucula is quite high, as each species seems to parasitise a single host.Verrucula arnoldaria – Calogaya arnoldiiVerrucula biatorinaria – Calogaya biatorinaVerrucula clauzadaria – Caloplaca clauzadeanaVerrucula coccinearia – Caloplaca coccineaVerrucula coronataria – Flavoplaca coronataVerrucula elegantaria – Xanthoria elegansVerrucula helvetica – Leproplaca cirrochroaVerrucula hladuniana – Flavoplaca marinaVerrucula inconnexaria – Caloplaca inconnexaVerrucula lactearia – Xanthocarpia lacteaVerrucula maritimaria – Flavoplaca maritimaVerrucula microspora – Variospora velanaVerrucula navasianaria – Flavoplaca navasianaVerrucula polycarparia – Flavoplaca polycarpaVerrucula protearia – Leproplaca proteusVerrucula pusillaria – Calogaya pusillaSome species previously classified in Verrucula have since been reduced to synonymy with other species, or have been transferred to different genera:
- Verrucula ahlesiana
- Verrucula cahirensis
- Verrucula egyptiaca
- Verrucula fraudulosa
- Verrucula fuscella
- Verrucula granulosaria
- Verrucula latericola
- Verrucula lecideoides
- ''Verrucula rheitrophila''