lichen

Have you ever walked through the woods and seen a crusty-looking shelf growing out of a tree? That is actually a lichen, a complex organism comprised of a fungus and its partner algae, the two parts interweaving to form one.

The word lichen appeared around 1600, and was drawn from the Greek leikhēn, meaning "what eats around itself." This is a good meaning for what the word represents, as lichen is comprised of fungus cells that literally surround the algae cells to form a mutualistic bond. Because of the crusty look of a lichen, the name has also been given to a number of skin diseases that present the same patchy look as the fungus-algae.

Primary Meanings of lichen

1.
n
any thallophytic plant of the division Lichenes; occur as crusty patches or bushy growths on tree trunks or rocks or bare ground etc.
2.
n
any of several eruptive skin diseases characterized by hard thick lesions grouped together and resembling lichens growing on rocks
Full Definitions of lichen
1

n any thallophytic plant of the division Lichenes; occur as crusty patches or bushy growths on tree trunks or rocks or bare ground etc.

Types:
show 11 types...
hide 11 types...
ascolichen
a lichen in which the fungus component is an ascomycete
basidiolichen
a lichen in which the fungus component is a basidiomycete
lecanora
any lichen of the genus Lecanora; some used in dyeing; some used for food
Roccella tinctoria, roccella
a source of the dye archil and of litmus
Usnea barbata, beard lichen, beard moss
greenish grey pendulous lichen growing on trees
horsehair lichen, horsetail lichen
any of several lichens of the genus Alectoria having a thallus consisting of filaments resembling hair
Cladonia rangiferina, arctic moss, reindeer lichen, reindeer moss
an erect greyish branching lichen of Arctic and even some north temperate regions constituting the chief food for reindeer and caribou and sometimes being eaten by humans
crotal, crottal, crottle
any of several lichens of the genus Parmelia from which reddish brown or purple dyes are made
Cetraria islandica, Iceland lichen, Iceland moss
lichen with branched flattened partly erect thallus that grows in mountainous and Arctic regions; used as a medicine or food for humans and livestock; a source of glycerol
manna lichen
any of several Old World partially crustaceous or shrubby lecanoras that roll up and are blown about over African and Arabian deserts and used as food by people and animals
archil, orchil
any of various lecanoras that yield the dye archil
Type of:
fungus
an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia
2

n any of several eruptive skin diseases characterized by hard thick lesions grouped together and resembling lichens growing on rocks

Types:
lichen planus, lichen ruber planus
an eruption of shiny flat-topped purplish (usually itchy) papules on the wrist and forearms and thighs
Type of:
disease of the skin, skin disease, skin disorder
a disease affecting the skin

Sign up, it's free!

Whether you're a student, an educator, or a lifelong learner, Vocabulary.com can put you on the path to systematic vocabulary improvement.