lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.fungi in the family 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 2003 by lichenologist Ted Essingler to contain s previously placed in the "Cetraria fendleri" species group. The genus names honors the American lichenologist Edward Tuckerman.
In 2017, Pradeep Divakar and colleagues used a then-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 ''Tuckermanella'' with '' Nephromopsis'', along with several other Parmelioid genera, 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 Parmelioid genera with ''Nephromopsis'' was not accepted in a later critical analysis of the temporal phylogenetic approach for fungal classification.
Description
''Tuckermanella'' lichens have small- to medium-sized foliose (leafy) thalli, and are generally brown to blackish-green in colour. They have continuous
pseudocyphella
Pseudocyphellae (singular ''pseudocyphella'') are structures in lichens that appear as tiny pores on the outer surface (the cortex of the lichen. They are caused when there is a break in the cortex of the lichen, and the medullary hyphae extend t ...
e (tiny pores that allow gas exchange) on the margins of their lobes. '' Tuckermannopsis'' and ''
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 ...
'' are similar in appearance, although species in those genera are typically larger and lack the continuous marginal pseudocyphellae.
Tuckermanella fendleri
''Tuckermanella'' is a genus of lichen-forming fungi in the family Parmeliaceae.
Taxonomy
The genus was circumscription (taxonomy), circumscribed in 2003 by lichenologist Ted Essingler to contain s previously placed in the "Cetraria fendleri" sp ...
Tuckermanella weberi
''Tuckermanella'' is a genus of lichen-forming fungi in the family Parmeliaceae.
Taxonomy
The genus was circumscription (taxonomy), circumscribed in 2003 by lichenologist Ted Essingler to contain s previously placed in the "Cetraria fendleri" sp ...