Fascinating Lichens of Sri Lanka

Sticta
Moon lichens, Crater lichens
Peltigerales Lobariaceae
100
Sticta is a cosmopolitan genus. The genus is most diverse in subtropical and
tropical regions. It is found mostly on tree bark and dead wood, and sometimes
on rocks and soil. Most Sticta species have cyanobacterial photobionts, while
some have green algae. It is commonly found in highly humid habitats and is
typically absent in drier parts of the country.
Sticta is a genus of large foliose lichens. It is characterized by the presence of
distinctive crater-like pits known as cyphellae in the lower surface of the thallus.
This genus can be distinguished by violet colour in a simple chemical test using
potassium hydroxide (KOH). This genus can be easily identified in its natural
habitat even by a non-lichenologist. The presence of cyphellae on the lower
surface immediately distinguishes Sticta from the closely related Lobaria and
Pseudocyphellaria.
Lobariaceae
Apothecia marginal to laminal, disc red brown- brown black, lecanorine or
biatorine, crenate or entire margin; Asci: 8-spored; Spores: colourless to brown,
fusiform, septate.
Chemistry No substance detected on Sri Lankan materials.
Sticta limbata
SL
Description Foliose. The thallus is reniform (kidney like) to irregular, and loosely
attached at one point. The lobes are broad, round, margins thickened and
densely sorediate. The upper surface is greyish green to brown when dry, and
greyish-brown to reddish when wet. The lower surface is pale yellowish brown to
grey-brown to dark reddish brown, Cyphellae sparse and rounded. Apothecia are
not seen on the material collected in Sri Lanka.
R
Fo
Lobariaceae
Status Rare species. Careful observation is needed, as it has only been spotted
only once. New record for Sri Lanka.
Habitat Seen in the humid high elevation montane forest of the Kalupahana-
Knuckles region only. This species could be restricted to montane forests. Found
at shady, highly humid sites, growing together with mosses.
Locations Kalupahana area in the Knuckles mountain region.
154 Fascinating Lichens of Sri Lanka
Fascinating Lichens of Sri Lanka 155