An isidium is a
vegetative
Vegetative describes vegetation. Vegetative may also refer to:
*Vegetative reproduction
Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is any form of asexual reproduction occurring in ...
reproductive structure present in some
lichens. Isidia are outgrowths of the
thallus
Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or " twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms ...
surface, and are
corticated (i.e., containing the outermost layer of the thallus), usually with a
columnar structure, and consisting of both fungal
hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one o ...
e (the mycobiont) and
algal cells (the photobiont). They are fragile structures and may break off and be distributed by wind, animals, and splashing raindrops.
In terms of structure, isidia may be described as warty, cylindrical,
clavate (club-shaped), scale-like, coralloid (coral-shaped), simple, or branched.
Examples of isidiate lichens include members of the genera ''
Parmotrema
''Parmotrema'' is a genus of lichen belonging to the family Parmeliaceae. It is a large genus, containing an estimated 300 species, with a centre of diversity in subtropical regions of South America and the Pacific Islands.
Members of the ge ...
'' and ''
Peltigera''.
See also
Soredium
References
External links
Ascomycetes glossary
Lichenology
Fungal morphology and anatomy
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