Fascinating Lichens of Sri Lanka

Parmotrema
Ruffle lichens, Scatter-rug lichens
Lecanorales Parmeliaceae
c.350
Parmotrema is a genus of large, pale grey or grey -green to yellow green, foliose
lichens with broadly rounded lobes. Most species are loosely attached, typically
marginally ciliate, and have a black, rhizinate undersurface with a naked, marginal
zone. This genus is best developed in tropical region. Species of this genus are
large, conspicuous foliose lichens.
More than 20 species are known from Sri Lanka up to date, the most common of
which tend to be Pantropical species. Recent research by Weerakoon and Aptroot
(2014) document many new records of this genus for Sri Lanka, including five
species that are new records for the Indian subcontinent. The Sri Lankan species
of Parmotrema occur on tree trunks, twigs, canopy branches, and on rocks of rain
forests, sub-montane, montane and dry deciduous forests throughout moister
areas.
Megalosporaceae
Cr
R
Megalospora tuberculosa
Description The thallus is crustose, corticate, continuous, wide, smooth, and
grey to whitish grey. Soredia are observed on some thalli. Apothecia are sessile,
and the disc is brown to black and margins yellowish brown.
Status Rarer than Megalospora sulphurata. Often seen on the mature trunks of
trees in shaded interiors or open forests.
Habitat Mostly found in humid mid elevation to high elevation forests above
700 m. Even found in disturbed sites and man-made vegetation types. Common
in home gardens in high elevation areas.
Species of Parmotrema are mainly separated by characteristics such as the
presence or absence of asexual propagules, and by medullary chemistry. Most
species known from Sri Lanka are overlooked and need taxonomic revision.
Studies are also needed to collect and identify the total diversity of this genus
in Sri Lanka, as it can be assumed that many more species remain undiscovered
in other habitats.
Apothecia laminal, lecanorine, generally pedicellate (stalked), disc brown;
Asci: 8-spored; Spores: colourless, simple, ellipsoid, thick walled.
Chemistry varies from species to species. Testing with K, PD and C is important
for identification of species.
Parmeliaceae
Locations Central highlands and high elevation forests in the wet zone.
118 Fascinating Lichens of Sri Lanka
Fascinating Lichens of Sri Lanka 119