Fascinating Lichens of Sri Lanka

Leptogium
Jellyskin lichens, Vinyl lichens
Peltigerales Collemataceae
180
Leptogium is most common in the tropical regions of the world but is widely
distributed in warm and cool temperate regions and has a few species which
reach the Arctic and Sub-Antarctic regions. It is found on bark, soil, rocks or
mosses in very wet or dry habitats.
This is a very conspicuous and common genus found in most natural and
disturbed habitats in the various climatic regions of Sri Lanka. More than 20
species are known from Sri Lanka in this genus. Some species are widely spread
across the island. Few recent collections were studied by Gothamie Weerakoon
and Andre Aptroot. Five new records of Leptogium were discovered for Sri
Lanka including one species that is a new record for the Indian subcontinent
(Weerakoon & Aptroot 2014). It is probable that many undiscovered species
could occur in particular montane communities. Therefore, further study is
required to discover the total diversity.
Pannariaceae
Fo
VC
Leioderma sorediatum
Description Small, olive grey foliose lichen found as a corticolous species in Sri
Lanka. The lobes are scalloped, and flat to slightly concave. Blue grey granular
soredia develop along the lobe margins. The upper surface is dark bluish green
when wet and pale olive greenish colour when dry. The lower surface has
scattered tufts of rhizines that are white to bluish, buff centrally, and white at the
margins. The upper surface is felt-like with tiny, very appressed hairs. Apothecia
are not seen on the material from Sri Lanka. Apothecia when present; are scarce,
usually only seen as pinkish initials. This species is very similar to Erioderma
sorediatum, but has longer lobes, is paler grey, and has many more tufted rhizines
on the lower surface.
In the field, this genus is difficult to distinguish from its sister genus Collema as
they have much in common, especially when their thalli are moist and swollen.
On the whole, Leptogium species are steel grey to grey or more reddish brown
when dry, with a smoother, more skin-like texture. Collema is never shiny in dry
or wet conditions, probably because it has no upper cortex.
Apothecia lecanorine, sessile, common in most species after rainy seasons, disc
orange-red, red brown to black; Asci: 4-8-spored; Spores: colourless, 4-celled
to muriform.
Chemistry All reactions negative.
Collemataceae
Status Very common in Horton Plains.
Habitat Mostly found in humid forests areas above 1400 m.
Locations Horton Plains, few places along the Pattipola road and Ohiya Road,
close to the Horton Plains entrance, Lover’s Leap - Nuwara Eliya, Knuckles and the
Kalupahana peaks of the Knuckles mountain region.
106 Fascinating Lichens of Sri Lanka
Fascinating Lichens of Sri Lanka 107