Fissurina capsulata is a species of corticolous (bark-dwelling) script lichen in the family Graphidaceae. Found in India, it was formally described as a new species in 2007 by Urmila Makhija and Bharati Adawadkar. The lichen is native to Kodaikanal, Tamil Nadu, where it was first identified near Daisy Bank in 1975.
This lichen has a pale green or dull green thallus, which is uneven and cracked. The ascomata, or fruiting bodies, are in form and range from 0.5 to 2.5 mm in length. These structures can be or branched and are generally the same colour as the thallus. The ascomata are immersed to slightly raised, with acute to subacute ends, and a have narrow to moderately broad that is not .
The , a protective layer surrounding the fertile, spore-bearing hymenium, is complete and non-striate, with a yellowish-brown colour that converges and is covered by a up to the top. The rounded apical region of this structure features a swollen "puff" that is interspersed with crystals. The hymenium is hyaline and 63âÂÂ71 üm high. The is distinct, thin, and pale, measuring 6âÂÂ8 üm in height. Fissurina capsulata has simple, long with warty tips, and short to moderately elongate measuring 4âÂÂ6 üm in length, also with warty tips. Its asci are 8-spored and measure 60âÂÂ70 by 8âÂÂ10 üm. The ascospores are hyaline, ellipsoidal, always contain 3 transverse septa, and measure 11âÂÂ16 by 4âÂÂ5 üm. They feature a large, conspicuous that is 3âÂÂ5 üm thick, narrow at one end, and thick at the other end.
The lichen's chemistry reveals that it does not contain any lichen products, and it tests negative on all standard spot tests. Fissurina capsulata shares a similar ascomatal structure with other Fissurina species but is distinguished by the size of its lirellae and unique ascospore features. Notably, it differs from F. subcontexta, F. marginata, F. rufula, and other similar species in various aspects, such as lirellae length, ascospore size, and the presence of different lichen substances.