lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Parmeliaceae.
Taxonomy
The genus was
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
in 1933 by Hungarian lichenologist
Vilmos Kőfaragó-Gyelnik
Vilmos Kőfaragó-Gyelnik (March 30, 1906 – March 15, 1945) was a Hungarian botanist and lichenologist.
Prior to earning his PhD in 1929 from Budapest University, he spent a year in Cairo to help organize a botanical museum. In 1930 he started ...
. The genus name ''Tuckermannopsis'' honours Edward Tuckerman (1817–1886), who was an American
botanist
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...
and professor who made significant contributions to the study of
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Amherst College
Amherst College ( ) is a private liberal arts college in Amherst, Massachusetts. Founded in 1821 as an attempt to relocate Williams College by its then-president Zephaniah Swift Moore, Amherst is the third oldest institution of higher educatio ...
type
Type may refer to:
Science and technology Computing
* Typing, producing text via a keyboard, typewriter, etc.
* Data type, collection of values used for computations.
* File type
* TYPE (DOS command), a command to display contents of a file.
* Ty ...
, and at that time, only species. The type species is a lichen, meaning it is erect, foliose, and with apothecia and pycnidia ( sexual and asexual reproductive structures, respectively) that are largely restricted to the margins of the lobes. Starting in the 1980s, the genus became a wastebasket taxon containing cetrarioid species of uncertain
taxonomic
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
affinities. In 2001,
Ingvar Kärnefelt
Jan Eric Ingvar Kärnefelt (born 1944) is a Swedish lichenologist.
Early life and education
Kärnefelt was born in Gothenburg, Sweden in 1944. His initial goal in his higher-level studies at University of Cologne in 1966–1967 was to become ...
and Arne Thell attempted to delimit ''Tuckermannopsis'' based on a combination of morphology and molecular phylogeny, although the DNA of only four species was used in the analysis. They accepted seven species in the genus, with distribution centres in western North America and Japan.
In 2017, Divakar and colleagues used a recently developed "temporal phylogenetic" approach to identify temporal bands for specific taxonomic ranks in the family Parmeliaceae, suggesting that groups of species that diverged within the time window of 29.45–32.55 million years ago represent genera. They proposed to synonymize ''Tuckermannopsis'' (and several other cetrelioid genera) with '' Nephromopsis'', so that all the genera within the Parmeliaceae are about the same age. Although some of their proposed taxonomic changes were accepted, the synonymization of the cetrelioid genera with ''Nephromopsis'' was not accepted in a later critical analysis of the temporal phylogenetic technique for use in fungal
systematics
Biological systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: cladograms, phylogenetic tre ...
.
Description
Characteristic of genus ''Tuckermannopsis'' include a thallus that is either foliose (leafy) or somewhat fruticose (shrubby) with an upper surface that is brown or greenish in colour; cylindrical
asci ASCI or Asci may refer to:
* Advertising Standards Council of India
* Asci, the plural of ascus, in fungal anatomy
* Accelerated Strategic Computing Initiative
* American Society for Clinical Investigation
* Argus Sour Crude Index
* Association of ...
with a small (a thickened apical region) and broad axial body; ascospores that are more or less spherical, measuring 4–8 μm in diameter; the absence of the secondary metabolite
usnic acid
Usnic acid is a naturally occurring dibenzofuran derivative found in several lichen species with the formula C18H16O7. It was first isolated by German scientist W. Knop in 1844 and first synthesized between 1933-1937 by Curd and Robertson. Usnic a ...
in the cortex, and the presence of various compounds in the medulla.
Tuckermannopsis ciliaris
''Tuckermannopsis ciliaris'' is a species of corticolous lichen, corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. It was first described by Erik Acharius in 1810, initially classified in the genus ''Cetraria''.The species ...
Melanohalea
''Melanohalea'' is a genus of foliose lichens in the family Parmeliaceae. It contains 30 mostly Northern Hemisphere species that grow on bark or on wood. The genus is characterized by the presence of pseudocyphellae, usually on warts or on ...
'', as '' Masonhalea inermis''. ''T. coralligera'' and ''T. fendleri'' have been moved to genus '' Tuckermanella'', created in 2003 to contain cetrarioid lichens previously placed in the "Cetraria fendleri" species group.