The algae that make up lichens are usually Nostoc commune and unicellular green algae in cyanobacteria, such as Synechococcus and citrus. Fungi belong to ascomycetes and basidiomycetes. Usually, the specific species of fungi and algae in lichens are fixed. In this symbiotic complex, algae contain photosynthetic pigments. Can carry out photosynthesis and provide nutrition for fungi; Fungi can absorb water and inorganic salts from the outside, provide them to symbiotic algae, and wrap the algae in them to avoid the dry death of algae cells caused by strong light. The two are interdependent and inseparable. The symbiotic relationship between fungi and algae is not equal, but fungi benefit more and reach a balance in this unequal state. Under natural conditions, these symbiotic algae or fungi cannot survive independently. Although lichen is a symbiotic complex of fungi and algae, its morphological characteristics are completely determined by symbiotic bacteria.
form
Lichen plants can be divided into shell lichens, leaf lichens and dendritic lichens according to their morphology.
Hard shell lichen
The plant is flat and shell-shaped, and the hyphae are firmly attached to the substrate, and some even extend into the substrate, which is difficult to peel off. Shell lichens account for about 80% of all lichens. For example, camellia on rocks and Callicarpa on bark.
foliose lichen
The plant is a thin and flat body, which looks like a leaf. It is loosely fixed on the substrate with false roots or false umbilicus and is easy to peel off from the substrate. For example, Cirrus, Tremella and Prunus born on grassland E, Prunus born on rocks or bark, etc.
Dendritic lichen
Plants are erect, with only the base attached to the substrate, usually branched and similar in shape to higher plants. For example, upright litmus, hanging branches of pineapples.
ecological environment
Most lichens are light-loving plants, and their habitats need fresh air. Not resistant to air pollution, therefore, lichens rarely grow in big cities and industrial parks. But lichens have strong cold tolerance and drought tolerance. It can sleep when it is dry and come back to life after the rain. It can grow on rocks, deserts or bark. For example, in places where other plants can't live, such as high mountains, permafrost and the North and South poles.