Sunday, February 27, 2011

PLANTS AND LICHENS OF THE IRISH UPLANDS

                                                                MAP LICHEN
The map lichen is a species of lichen, Rhizocarpon geographicum, which grows on rocks in mountainous areas of low air pollution. Each lichen is a flat patch bordered by a black line of spores. These patches grow adjacent to each other, leading to the appearance of a map or a patchwork field.
Map lichen is a lichen widely used by climatologists in determining the relative age of deposits, e.g. moraine systems, thus revealing evidence of glacial advances. The process is termed lichenometry.
Lichenometry is based on the assumption that the largest lichen growing on a rock is the oldest individual. If the growth rate is known, the maximum lichen size will give a minimum age for when this rock was deposited.
Growth rates for different areas and species can be obtained by measuring maximum lichen sizes on substrates of known age, such as gravestones, historic or prehistoric rock buildings, or moraines of known age (e.g. those deposited during the Little Ice Age).


SUNDEW
The Sundew carnivorous plant is one of the many types of carnivorous or insectivorous plants that catch insects and small animals in order to acquire additional nutrients. This is because of the fact that they are usually found in areas with a very poor soil quality. These carnivorous plants got its name because of the drops of mucilage that are found on their leaves which resemble the dewdrops that appear every morning. This mucilage of the Sundew carnivorous plant is its main tool for catching prey. This causes any insect or small animal that lands on the leaves to stick to it until it is digested and absorbed by the plant.
They are found in almost all areas in the world especially in areas where there is enough sunlight and water but not enough soil nutrients. These usually include bogs, swamps and forest floors.
These plants are also best described by the tentacles which are found in their stems and leaves. These are the main source of their sticky mucilage as well as their digestive enzymes. They curl up or move in response to any potential prey and these further decrease any possibility of escape. The leaves of most species of the Sundew can cover their prey in a matter of seconds so as to coat it with the largest amount of sticky enzymes and digestive juices as possible.

No comments:

Post a Comment