Fascinating Lichens of Sri Lanka

Coenogonium
Pixie-hair lichens
Ostropales Coenogoniaceae
80
Coenogonium is a genus that mainly occurs in the subtropical and tropical
regions of the world. The genus consists of species with a green to greyish
green crustose or filamentous thallus. Most filamentous species of Coenogonium
consist of lichenized filaments of Trentepohlia (green alga) which are similar in
appearance to unlichenized Trentepohlia, which are present in the same habitats.
It is therefore essential to find thalli for filamentous species with fruiting bodies,
not only to be able to name the species but also to be sure you have a lichen.
Only few species are known from Sri Lanka up to date, the most common of which
tends to be a pantropical species. Recent research by Weerakoon and Aptroot
(2014) documented a new record of this genus for the Indian subcontinent and
Sri Lanka.
Coccocarpiaceae
Fo
VR
IC
Coccocarpia stellata
Description Foliose. The thallus is characterized by linear, thin lobes that are
flat, branched and dissected. Lobes are apically often very slightly wider and
dark grey. The upper surface is bluish grey, while the lower surface is pale and
has white rhizines. The lower surface is pale to black. Rhizines are pale to black.
Apothecia are abundant and originate from lobe margins. Apothecial discs are
orange brown and flat. Apothecia have a thin, slightly raised concolourous (same
colour) margin.
The Sri Lankan species are distinctive epiphytes that occur on smooth-barked
trunks, and on mossy rocks of sub-montane, and montane forests throughout
undisturbed, high elevation, humid areas.
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 similar habitats.
Apothecia common, sessile, convex to flat, disc yellowish to pale orange brown;
Asci: mostly 8-spored; Spores: colourless, ellipsoid, 1-2 celled.
Chemistry No lichen substances.
Coenogoniaceae
Status Seen on mature leaves and thin branches in settings that are more or
less exposed to light. New record for the Indian subcontinent and Sri Lanka.
Habitat Mostly found in humid, high elevation forests above 1600 m, and a
forest-dwelling species.
Locations This species can be found in a few places along the Nuwara Eliya
- Pattipola road that goes up to Horton Plains. Restricted to Horton Plains and
Hakgala strict nature reserve.
64 Fascinating Lichens of Sri Lanka
Fascinating Lichens of Sri Lanka 65