Lichens
Lichen
Flora
At a Glance | |
Family | 3 Kingdoms, Monera, Protista and Fungi |
Seasonality | All year |
Height | negligible |
SA Tree Number | n/a |
Conservation Status | n/a |
Description
Lichen does not live as a parasite. They use the plant as a substrate only.
Lichen is a composite, symbiotic organism made from members of 2 or 3 Kingdoms.
The dominant partner is fungus (they take their name from the particular fungus), which is incapable of making its own food; they are either parasites or decomposers. They therefore cultivate partners that manufacture food by photosynthesis. The partner can either be an alga or cyanobacteria and sometimes both.
The result is little balls of algae wrapped in threads of fungus, called soredia.
They can be flat and leaf-like (foliose), crust-like buried in a tree's bark or rocky crevice (crustose), shrub-like (fruticose) or scaly (squamulose).
They are generally silver-grey but can also be yellow, orange and blue.
Distribution
Anywhere where there is sufficient light, moisture, clean air and freedom from competition.
Flower - Fruit
Small pieces breaking off and being blown to a new substrate spread most lichens.
Uses
Tend to be very sensitive to air pollutants and can be used to map various pollutants, ozone levels or the presence of metal contamination.
The leaf-like lichens are used in models.
Although lichens have been used in traditional medications, a soap scent and wool dye, the most important commercial use is in the making of litmus paper.
Those lichens that grow on rocks contribute to soil production; both through pressure and chemical reactions; certain acids dissolve the rock surface, freeing minerals, which enrich soil.
Local Information
Found throughout the reserve.
Those on trees can be found mainly in shady areas along the river streams.
Those on rocks will be best spotted along the rivers and streams – the rocks in the Nkutu Gorge near the waterfalls have some excellent examples particularly of the orange species.
Interesting Facts
They tend to live for many years and lichens, which are hundreds of years old, are used to date the rocks on which they grow.