''Rusavskia indochinensis'' is a species of
saxicolous (rock-dwelling)
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.[Teloschistaceae
The Teloschistaceae are a large family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. The family, estimated to contain over 1800 species, was extensively revised in 2013, including the creation o ...]
.
It occurs in India and China.
Taxonomy
''Rusavskia indochinensis'' was described as a new species in 2020 by lichenologists
Sergey Kondratyuk
Sergey Yakovlevich Kondratyuk ( uk, Сергій Якович Кондратюк) (born 17 May 1959) is a Ukrainian botanist specialising in lichenology. His research deals with the taxonomy, floristics, ecology and geography of lichens and lic ...
, Gaurav Kumar Mishra,
Sanjeeva Nayaka
Sanjeeva Nayaka (Hindi: संजीव नायक; Kannada: ಸಂಜೀವ ನಾಯಕ) is an Indian lichenologist. He is Senior Principal Scientist at CSIR-National Botanical Research Institute (CSIR-NBRI), Lucknow. He is in charge of th ...
, and
. The
species epithet ''indochinensis'' refers to the southern part of the Asian continent, which is where this species has been identified. The
type specimen was collected in India, specifically in
Uttarakhand's
Chamoli district, before
Malari
Malari in the Dhauli Ganga valley of the Nanda Devi Biosphere reserve is a small village near the Tibet border. This area has been declared as a world heritage site. Located 61 km from Joshimath, the nearest ''Tehsil,'' in Chamoli District ...
on the way to
Niti Niti can refer to:
* Nickel titanium alloy or Nitinol
* Shape memory alloy
In metallurgy, a shape-memory alloy (SMA) is an alloy that can be deformed when cold but returns to its pre-deformed ("remembered") shape when heated. It may also be call ...
at an altitude of .
While ''Rusavskia indochinensis'' is categorically part of the ''Rusavskia'' branch based on its
Internal transcribed spacer nrDNA
Ribosomal DNA (rDNA) is a DNA sequence that codes for ribosomal RNA. These sequences regulate transcription initiation and amplification, and contain both transcribed and non-transcribed spacer segments.
In the human genome there are 5 chromos ...
phylogeny, its resemblance to species of the genus ''Zeroviella'' suggests the need for more
molecular
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...
data for precise classification. Chinese specimens, in particular, require further molecular examination to determine their exact status.
Description
The
thallus of ''Rusavskia indochinensis'' can span several centimetres, with individual thalline measuring between in length. The lobe edges tend to bend downwards, making them look wider from the underside. The upper surface is matte, transitioning in colour from deep yellow at the tips to greyish or greenish yellow towards the centre.
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 on the outer surface for gas exchange) can sometimes be observed on this surface. The lichen's underside is typically white but turns yellow towards the tips.
, which are the reproductive structures of the lichen, are relatively small, with a diameter ranging from . These are coloured bright yellow to dull yellow and are raised significantly above the thalline lobe surface.
Similar species
''Rusavskia indochinensis'' shares similarities with members of the genus ''
Zeroviella
''Zeroviella'' is a genus of lichen-forming fungi in the subfamily Xanthorioideae of the family Teloschistaceae. It has eight saxicolous (rock-dwelling) species. ''Zeroviella'' was segregated from '' Rusavskia'', a closely related genus, in 2015 ...
'', particularly ''
Z. digitata'', ''
Z. domogledensis'', and ''
Z. papillifera''. The primary distinguishing feature of ''R. indochinensis'' from these species is the absence of isidia-like formations. When compared to ''Zeroviella digitata'', which is native to southeastern Europe, ''R. indochinensis'' has larger measurements of its lobes and secondary sublobules.
Habitat and distribution
This lichen predominantly colonises
siliceous rock
Siliceous rocks are sedimentary rocks that have silica (SiO2) as the principal constituent. The most common siliceous rock is chert; other types include diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or ...
outcrops. While its presence has been recorded in India and China, its distribution remains scattered and sporadic across the southern part of the Asian continent.
References
{{Taxonbar, from=Q108331441
Teloschistales
Lichen species
Lichens described in 2020
Lichens of China
Lichens of India
Taxa named by Sergey Kondratyuk
Taxa named by Dalip Kumar Upreti