Fascinating Lichens of Sri Lanka

Leioderma
Treepelt lichen, Mouse ears
Peltigerales Pannariaceae
c.10
Leioderma is mainly found in the Southern Hemisphere. It is extremely rare in the
Northern Hemisphere and is only known to occur in a few localities. It is a small
genus. Most species are epiphytes found on shrubs and trees. They are restricted
to moist habitats and found in undisturbed conditions at the scrubby margins of
montane forests in Sri Lanka.
Thus far, only one species, Leioderma sorediatum has been found in Sri Lanka.
Namely, in Horton Plains and a few adjacent localities, a few places in Nuwara
Eliya, Kalupahana and the Knuckles Peak of the Knuckles mountain range. The
distribution known so far demonstrates that this genus is confined to high
elevation montane forests.
Cr
VC
SL
Lecanora tropica
This species is corticolous in Sri Lanka. The thallus is foliose and has loosely
attached rosettes. This small genus is mostly related to Pannaria and Parmeliella.
It is probably most similar to Erioderma sorediatum (an extremely rare species in
Sri Lanka), but has longer lobes, is paler grey, and has many more tufted rhizines
on the lower surface. It is possible that more species could occur in the highlands
in montane communities which have not yet been observed.
Lecanoraceae
Description The thallus is dispersed-verrucose (having small rounded processes)
to continuous or byssoid (thallus is comprised of loosely interwoven threads and
appears rather cottony), and yellowish white grey in colour. Soredia are absent. A
black prothallus is present. Apothecia are sessile, with a pale to dark brown disc.
The apothecial margin is concolourous (same colour as the thallus), thick, and
verrucose.
Apothecia round, biatorine, disc pale to red brown; Asci: 8-spored; Spores:
colourless, and simple.
Chemistry hymenium I+ persistent blue (except one species in the genus)
Pannariaceae
Chemistry Thallus and apothecial margin K+ yellow, C+ Orange, PD + yellowish
orange.
Status Very common. New record for Sri Lanka.
Habitat Mostly found in humid forest areas above 400 m. Occurs on the bark of
trees. This species is pantropical.
Locations Kandy, Kegalle, Sinharaja forest, Gampaha, Matale, Nuwara Eliya,
Ampara, and Kurunagala.
104 Fascinating Lichens of Sri Lanka
Fascinating Lichens of Sri Lanka 105