Lichenothelia
From Wikipedia, the free encyclopedia
| Lichenothelia | |
|---|---|
 | |
| Lichenothelia sp. | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Lichenotheliales |
| Family: | Lichenotheliaceae |
| Genus: | Lichenothelia D.Hawksw. (1981)[1] |
| Type species | |
| Lichenothelia scopularia (Nyl. D.Hawksw. (1981) | |
| Synonyms[2] | |
| |
Lichenothelia is a genus of fungi in the family Lichenotheliaceae.[3] The genus was established in 1981 by David L. Hawksworth and includes 13 recognised species. These fungi form thin black crusts on rocks and other surfaces, producing distinctive dome-shaped fruiting bodies that eventually develop a dish-like depression in the centre. The genus represents the type of its own order, Lichenotheliales, which was created to accommodate these and related rock-dwelling fungi.
The genus Lichenothelia was introduced by David L. Hawksworth in 1981 as a new name for the so-called Microthelia aterrima species group after studies showed that this assemblage is unrelated to the bark-dwelling (corticolous) fungi traditionally treated in Microthelia. Earlier attempts to segregate the group—such as Santo Garovaglio's illegitimate Anzia (1868) and Edvard Vainio's later, non-typical use of Microthelia—are regarded as nomenclaturally invalid, and both are listed as synonyms of Lichenothelia.[1]
Hawksworth selected Lichenothelia scopularia (originally Verrucaria scopularia) as the type species, and he accepted two members in the genus: L. scopularia and L. metzleri. He also noted a third, as-yet undescribed North-American taxon displaying a slightly different development. The two described species differ mainly in ascospore size, septation and iodine reactions of the ascus wall.[1]
The systematic placement of Lichenothelia was initially uncertain. Hawksworth observed that ascus structure shows features of both the Lecanorales and the Dothideales, suggesting the genus may represent an evolutionary link between these lineages. Developmental studies by Henssen and Jahns led them to assign the group provisionally to the Dothideales (family Mycoporaceae), whereas other species formerly held in Microthelia were transferred to the Pleosporales.[1]
In a major revision of the Dothideomycetes, Knudsen, Muggia and Hyde erected the new order Lichenotheliales to accommodate Lichenothelia as its type genus. The order encompasses fungi that are either non-lichenised or live on existing lichens. They occur epiphytically on plant surfaces, grow endolithically within rock, or sit on the surface of other lichens. All members produce double-walled (bitunicate) asci—often turning blue in the K/I test—formed either in perithecioid, ostiolate ascomata or in non-ostiolate stromata. It differs from the superficially similar Lichenostigmales (Arthoniomycetes) in having a hamathecium and in containing several rock-dwelling species that are not lichenicolous.[4]