What are lichens?

Question

What are lichens ? A kingom, phylum, class, order, family??? And what is their botanical name

Answer 1

Lichens are composed of a fungi and moss, its a symbiotic relationship between those two organisms

Answer 2

http://en.wikipedia.org/wiki/Lichen

Answer 3

What are Lichens?

An astonishing partnership between two very different organisms

Colonies which may be 9,000 years old

Colourful dyes for clothes

Packing for ancient Egyptian mummies!

Pollution indicators

High mountain dwellers and Arctic survivors

Uses

Lichens have had a wide variety of uses over the ages. Before the advent of modern dyes they were extremely important sources of dyes for clothing. Different lichens yielded different dye colours and they could be mixed to produce a wide variety of colours.

Lichens also have an interesting chemistry and produce a large number of acids, many of them found only in lichens. The litmus dye used so widely as an acid/alkaline indicator in chemistry comes from lichens. Some species also have antibiotic properties. Some of the lichen acids are utilized in drugs that can be more effective than penicillin.

One of the more bizarre uses of lichens from the past is as packing material for ancient Egyptian mummies!



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Answer 4

A type of newt

Answer 5

Lichens are difficult to classify because they are two different organisms.  They are classified in the Kingdom Fungi, Phylum Mycologist.  However, mycologists are suggesting that we classify them in the Kingdom Fungi and name them based on their fungal component.  Lichens are subdivided into three groups based on their morphology: Crustose, Fruticose, and Foliose.

Answer 6

you have posted it in the wrong section because it has got nothing to do with botany.

Lichens- A fungus, usually of the class Ascomycetes, that grows symbiotically with algae, resulting in a composite organism that characteristically forms a crustlike or brancLichens are formed from specialized groups of parasitic fungi; this association is one of a controlled parasitism rather than mutualism. Thus, the photobionts that lichen fungi slowly parasitize should be considered victims and not partners.

Lichen-forming fungi share two characteristics with fungi that parasitize plants: concentric bodies and specialized branches of hyphae (haustoria) that penetrate host cells and absorb nutrients from them.

Lichens have a worldwide distribution and grow on almost any inanimate object. They are among the hardiest of organisms and thrive in some of the Earth's harshest environments, such as polar regions, deserts, and high mountains.

The name given to a lichen applies only to the mycobiont, while the photobiont has a separate name. Most of the 15,000 lichen-forming fungi are in the fungal class Ascomycotina (ascolichens). Approximately a dozen species of basidiomycetes form lichens. Lichens that do not have sexual reproduction (Lepraria) are placed in the Lichenes Imperfecti.

Photobionts of lichens are either green algae or cyanobacteria. The most common photobiont is Trebouxia. This unicellular green algae has never been found in the free-living state. It is believed that Trebouxia is a lichenized and highly modified form of the filamentous alga Pleurastrum terrestre.

The basic metabolic processes of lichens are photosynthesis, respiration, and nitrogen fixation. Lichens have adapted these processes to different conditions of light, temperature, day length, and water. The mycobiont causes the photobiont to excrete most of the carbon that it fixes during photosynthesis. Only a single type of compound is excreted. The mycobiont absorbs these compounds and converts them to mannitol, its own storage compound. See also Plant respiration.

Nitrogen-fixing lichens are common and contribute nitrogen to different ecosystems when they decay. In cyanolichens the mycobiont inhibits the nitrogen-assimilating enzymes of the cyanobiont, causing it to release most of the ammonia it produces. The ammonia is absorbed by the mycobiont and used to make proteins and nucleic acids. See also Nitrogen fixation.

Lichens produce several hundred secondary compounds that accumulate as crystals in the thalli, often at high concentrations. These compounds may protect the slow-growing thalli from harmful bacteria, fungi, and insects and may play a regulatory role in the interactions between bionts. Lichen secondary compounds represent a new class of antibiotics in an age where standard antibiotics such as penicillin are becoming ineffective against antibiotic-resistant microbes. Secondary compounds are used extensively by taxonomists to characterize new taxa of lichens (chemotaxonomy).

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