Lichen vs Rust

Lichen [ ˈlaɪ kən ]

A lichen (/ˈlaɪkən/ LY-kən, also UK: /ˈlɪtʃən/ LICH-ən) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.[4] Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but lichens are not plants. They may have tiny, leafless branches (fruticose); flat leaf-like structures (foliose); crust-like, adhering tightly to a surface (substrate) like a thick coat of paint (crustose);[5] a powder-like appearance (leprose); or other growth forms.[6]

• any complex organism of the group Lichenes, composed of a fungus in symbiotic union with an alga and having a greenish, gray, yellow, brown, or blackish thallus that grows in leaflike, crustlike, or branching forms on rocks, trees, etc.
• Pathology.
• any of various eruptive skin diseases.
• to cover with or as if with lichens.
• an organism that is formed by the symbiotic association of a fungus and an alga or cyanobacterium and occurs as crusty patches or bushy growths on tree trunks, bare ground, etc. Lichens are now classified as a phylum of fungi (Mycophycophyta)
• pathol
• any of various eruptive disorders of the skin
• Any of various skin diseases characterized by patchy eruptions of small, firm papules.
• The mutualistic symbiotic association of a fungus with an alga or a cyanobacterium, or both. The fungal component of a lichen absorbs water and nutrients from the surroundings and provides a suitable environment for the alga or cyanobacterium. These live protected among the dense fungal hyphae and produce carbohydrates for the fungus by photosynthesis. Owing to this partnership, lichens can thrive in harsh environments such as mountaintops and polar regions. The more familiar lichens grow slowly as crusty patches, but lichens are found in a variety of forms, such as the tall, plantlike reindeer moss. The association between the different organisms in a lichen is so close that lichens are routinely referred to as a single organism, and scientists classify lichens using the name of the fungal component.

Rust [ rʌst ]

Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3), and is typically associated with the corrosion of refined iron.

• Also called iron rust .
• the red or orange coating that forms on the surface of iron when exposed to air and moisture, consisting chiefly of ferric hydroxide and ferric oxide formed by oxidation.
• any film or coating on metal caused by oxidation.
• a stain resembling this coating.
• any growth, habit, influence, or agency tending to injure, deteriorate, or impair the mind, character, abilities, usefulness, etc.
• Plant Pathology.
• any of several diseases of plants, characterized by reddish, brownish, or black pustules on the leaves, stems, etc., caused by fungi of the order Uredinales.
• Also called rust fungus .
• a fungus causing this disease.
• any of several other diseases of unknown cause, characterized by reddish-brown spots or discolorations on the affected parts.

• bog
• morass
• swamp

• decay
• blight
• corruption
• decomposition
• dilapidation
• mold
• oxidation
• rot
• wear

• 1. The stone stairway was covered with lichen.
• 2. Maybe I was on some damp lichen.
• 3. Their names grow shallow with lichen.
• 4. The triumphant plant, a combination of lichen and cactus, certainly would look weird to the eyes of man.
• 5. These majestic stones, flecked with orange and white lichen, are the last of thousands that once littered the prehistoric landscape.
• 6. The walls are black and slimy with lichen and pigeon shit.
• 7. On the upper levels of the church lichen deposits have reached unacceptable levels.
• 8. We have investigated 103 patients with oral lichen planus for serological or haematological evidence of coeliac disease.
• 9. I heard the ointment is effective for treating lichen.
• 10. The rock is full of lichen.

• 1. Idleness is the rust of mind. 
• 2. Better wear out than rust out. 
• 3. Idleness makes the wit rust.
• 4. Sloth, like rust, consumes faster than labor wears. 
• 5. Idleness is the rust of the mind. 
• 6. Rest breeds rust.
• 7. It is better to wear out than to rust out. 
• 8. Rust has corroded the steel rails.
• 9. Iron exposed to damp air will rust.
• 10. There were large patches of rust on the car.