Sunday, March 9, 2014

The shrubby ramalina

Ramalina - Ramalina durieui - Ramalina
The ramalina are a genus of lichens with a typical shrubby structure. They are very different from the lichens we are used to seeing on walls, rocks and stones. At least one species of ramalina can be found in the Maltese islands. Instead of having the familiar circular shape, this species, which one finds growing on trees at Buskett and the nearby valley of Girgenti, has the shape of shredded grey leaves stuck onto a branch or twig.
The genus ramalina consists of about 240 species. They are found widely around the world in various habitats.
In the Maltese islands about two hundred species have been recorded. Most are coloured patches decorating stone or wood surfaces. Lichens are very slow growing and it takes a very long time for a freshly exposed surface to become covered in lichen.
Lichens are usually the first organisms to colonise bare surfaces. They can survive in inhospitable environments because they can make the most out of two worlds. A lichen consists of two organisms, a fungus and a green algae or a cyanobacterium living together symbiotically.
It was only in 1867 that the dual nature of lichens was discovered by Simon Schwender, a Swiss professor of botany who was director of the Botanical Gardens in Basel. His discovery was not immediately accepted as a number of leading lichenologists did not believe that a species could be made up of two different organisms.
Some species of lichen are eaten regularly. While some species are considered a delicacy others are resorted to only in times of famine. In Northern Europe a lichen was cooked as a bread, porridge and even eaten as a salad. 
Lichens have been used for centuries to produce dyes especially red and purple. They have also been used as a source of primitive antibiotics. Some compounds in lichens are useful as they can reduce harmful rays from the sun. 
This article was published in The Times of Malta on  February 2014.

No comments:

Post a Comment