''Astrothelium mesoduplex'' is a species 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.[Trypetheliaceae
The Trypetheliaceae are a family of mainly lichen-forming fungi in the order Trypetheliales.
Genera
*'' Alloarthopyrenia'' – 1 sp.
*''Aptrootia'' – 3 spp.
*'' Architrypethelium'' – 8 spp.
*''Astrothelium'' – ca. 275 spp.
*'' Bathel ...]
.
It is similar to ''
A. flavoduplex'' but has larger and lacks
lichexanthone. This lichen species has been found only in Brazil, particularly in
primary forests.
Taxonomy
''Astrothelium mesoduplex'' was
formally described as a new species in 2016 by lichenologists
André Aptroot
André Aptroot (Heemskerk, 1961) is a Dutch mycologist and lichenologist.
In 1993 he did his PhD at the University of Utrecht under the supervision of Robbert Gradstein (nl). His dissertation was titled "Systematic studies on pyrenocarpous li ...
and Marcela Cáceres. The
type specimen was collected by the authors in the
Parque Natural Municipal de Porto Velho (
Porto Velho,
Rondônia
Rondônia () is one of the 26 states of Brazil, located in the northern subdivision of the country (central-western part). To the west is a short border with the state of Acre, to the north is the state of Amazonas, in the east is Mato Grosso, ...
), where it was found growing on a twig in a primary
rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
.
Description
The
thallus of ''Astrothelium mesoduplex'' is , smooth, somewhat shiny, and continuous, with an olive-green colour. It covers areas up to in diameter and is approximately 0.1 mm thick. The thallus is surrounded by a black
prothallus line about 0.2 mm wide and does not induce
gall
Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...
formation on the host bark. The ascomata are spherical, 0.4–0.6 mm in diameter, and immersed in groups of about 3–50 in . The pseudostromata have a surface different from the thallus, raised about 1 mm above the thallus, and are oval to irregular in outline, up to 3 mm wide. They are yellow to orange in colour, with a pale yellow interior. The wall of the ascomata is dark brown all around, and measures up to 40
μm
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
thick. The
ostiole
An ''ostiole'' is a small hole or opening through which algae or fungi release their mature spores.
The word is a diminutive of "ostium", "opening".
The term is also used in higher plants, for example to denote the opening of the involuted ...
s are apical, not fused, flat to convex, and brown. The is not with oil globules. The
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 ...
contain 8 ascospores, which are
hyaline
A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none.
Histopathology
Hyaline cartilage is ...
, with about 22–30 transverse
septa, to clavate, 90–100 by 20–23 μm in size, with rounded ends and angular with mostly oblique septa.
Habitat and distribution
''Astrothelium mesoduplex'' is found on smooth bark of trees in primary forests and is currently known only from Brazil. It has been observed in Porto Velho, Rondônia, at the Parque Natural Municipal de Porto Velho, and Fazenda São Francisco, north of Porto Velho.
References
{{Taxonbar, from=Q107503873
mesoduplex
Lichen species
Lichens described in 2016
Lichens of Brazil
Taxa named by André Aptroot
Taxa named by Marcela Cáceres