''Fissurina khasiana'' is a species of corticolous (bark-dwelling)

script lichen A script lichen, or graphid lichen, is a member of a group of lichens which have spore producing structures that look like writing on the lichen body. The structures are elongated and narrow apothecia called lirellae, which look like short scribbles ...

in the family

Graphidaceae The Graphidaceae are a family of lichens in the order Ostropales. Distribution and ecology The vast majority of Graphidaceae species are restricted to the tropics. Most Graphidaceae species are epiphytic (i.e. they grow only on plants). Gener ...

. It is found in India, specifically in the evergreen forests of Upper Shillong in the Khasi Hills; its species name is derived from the region where it was first collected. The lichen was formally described as a new species in 2007 by Urmila Makhija and Bharati Adawadkar.

Description

The thallus of ''Fissurina khasiana'' is greyish-green in colour, with a smooth and cracked surface that appears . Its ascomata, or fruiting bodies, are in form and measure 2–4 mm in length and 0.1 mm in width. They can be simple or irregularly branched, immersed, and end in a sharp or somewhat acute tip. The of the ascomata is narrow, black, and indistinct. The is present at the base, non-striate, and non-, with a round and somewhat puffed appearance. It is mostly convergent to slightly divergent and covered by a up to the top. The

hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...

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 ...

, not , and ranges from 80 to 100

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 ...

in height. The is also hyaline. are simple, long, and thin, with slightly elongate, warty tips. are short and mostly smooth, occasionally having warty tips.

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 ...

are cylindrical, 6–8-spored, and measure 50–60 by 6–8 μm. The ascospores are

ellipsoid An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...

al with 3 transverse septa, and measure 16–19 by 8–10 μm and a 1.6–2 μm-thick . Chemical spot tests reveal that the thallus of ''Fissurina khasiana'' has K+ (yellow-red), C−, KC−, P+ (orange), and UV− reactions. The lichen contains both constictic and

stictic acid Stictic acid is an aromatic organic compound, a product of secondary metabolism in some species of lichens. Stictic acid is the subject of preliminary biomedical research. Stictic acid has cytotoxic and apoptotic effects ''in vitro''. Computation ...

s. The ascomatal structure of the species is considered to be of the "comparilis-type." However, ''Fissurina khasiana'' is distinct from other species in this group due to the presence of both stictic and constictic acids in its thallus. ''Fissurina khasiana'' has an ascomatal structure that is intermediate between ''

Fissurina inquinata ''Fissurina'' is a genus of lichenized fungi in the family Graphidaceae. The genus was first described by the French botanist Antoine Laurent Apollinaire Fée in an 1825 publication. Species *''Fissurina abdita'' *''Fissurina adscribens'' * ...

'' and '' F. triticea''. It is distinguished by its relatively minor "puffing" and a non-carbonized exciple, setting it apart from both ''F. inquinata'', which has little "puffing" and a carbonized exciple, and ''F. triticea'', which has strongly "puffed" ascomata and a non-carbonized exciple. Additionally, ''Fissurina triticea'' has larger and more rounded ascospores, measuring 15–20 by 10–15 μm.

References

{{Taxonbar, from=Q17387864 khasiana Lichen species Lichens described in 2007 Lichens of India