A - no population size reductions provided
EN B2ab(iii)- AOO < 500 km2, locations <5, continuing decline in habitat quality
C1 - number of mature individuals < 250, but no decline values provided
EN C2a(i) - <250 individuals, inferred continuing decline, number of individuals in largest subpopulation is <250
EN D - Number of mature individuals <250
Thallus corticolous; surface whitish, cracked, slightly verrucose to rimose-like. Prothallus pale whitish in inner part, pale brownish at peripherial regions; forming a dark brownish, ca. 0.2 mm wide border line when it meets with other lichen thalli. Ascomata rounded, 0.5–1 mm in diam., solitary to grouped of 1–3, giving a pseudo-stromatic appearance, constricted at base; margin smooth, entrie, ±whitish/concolorus with the thallus, usually level with disc, 50–170 µm thick, corticated, filled with some yellow-brownish gelatinous substance, clearing in K, 15–30 µm thick, medullary portion filled with algal cells, hyphae encrystated with minute crystals; disc with thick white pruina with even surface, brownish when pruina removed, plane to slightly convex. Excipulum thin to inconspicuous, hyaline to pale brownish, 8–10 µm thick, transition zone between excipulum and hymenium I+ blue. Epithecium dark brownish, with grayish gelatinous materials, 30–40 µm thick. Hymenium hyaline, not inspersed, hymenial strands present in some sections, 75–105 µm high, I+ orangish-red. Hypothecium pale- to dark brownish, gradually becomes carbonaceous at base, 60–120 µm high, K+ slightly olivaceous. Asci 8-spored. Ascospores hyaline, 3-septate, fusiform with blunt ends, straight to curved, 22–31.5 × 3.8–5.2 µm.
Pycnidia not seen.
Chemistry: Thallus K–, C+ red, P–, UV–; erythrin and lecanoric acid detected in TLC.
Two subpopulations are known, one from the west coast of India (Gujarat), and the second from the southern coast of the Arabian
Peninsula and on Socotra Island in Yemen.
EOO: 857,561.281 km2
AOO: 208 km2
Number of individuals known: 53 [India: 51; Yemen: 2]
The EOO seems to be large, but both the populations (India and Yemen) are separated by the ocean. Indian distributions come under the Marine National Park of Gujarat coast, the species mainly growing on mangrove plants. The area is highly threatened by tourism, large scale fishing, and shipyard activities.
The species was described in 2013 based on the type specimen from India (with three additional specimens), and two additional collections from Yemen. During the revisionary studies on Arthoniales in India, Additionally, 47 individuals were able to collect from the same west coast of Gujarat. However, the species were not able to collect from other coastal regions of India.
About 55 individuals were found on the west coast of Gujarat (India). Mainly growing on the bark of mangrove plants. Most of the areas are under Marine National Park and adjacent Islands. The species was unable to collect from the other coastal regions of India. So far, two collections are known from Yemen (one each from the Arabian Peninsula and Socotra Island).
So far, the species is known to be growing on the bark of mangrove trees and shrubs, and on Prosopis juliflora in nearby inland areas.
The species is threatened by tourism, large scale fishing, and shipyard activities. Especially, the local people are collecting the Prosopis juliflora on large scale for firewood purposes. Indian west coasts are vulnerable to tsunamis and cyclones.
1. Tehler, A., Ertz, D., and Irestedt, M. 2013. The genus Dirina (Roccellaceae, Arthoniales) revisited. The Lichenologist 45(4): 427-476.
2. Ingle, K.K. 2018. Morphotaxonomic and ecological studies on mangrove lichens of Gujarat state, India. Ph.D. thesis submitted to Barkatullah University, Bhopal, Madhya Pradesh.
3. S. Joseph. 2015. Revisionary studies on the family Roccellaceae sensu lato in India. Flora of India Project, Final Report submitted to the Botanical Survey of India, Kolkata.