thallus

American  

[thal-uhs] / ˈθæl əs /

noun

Botany, Mycology.

thalli, plural thalluses plural

1. a simple vegetative body undifferentiated into true leaves, stem, and root, ranging from an aggregation of filaments to a complex plantlike form.

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thallus British  

/ ˈθæləs /

noun

1. the undifferentiated vegetative body of algae, fungi, and lichens

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thallus Scientific  

/ thăl′əs /

thalli plural

1. A type of body found among plants and fungi that is not differentiated into roots, stems, or leaves. Thalli are found among lichens, mosses, liverworts, and many algae, as well as the gametophyte generations of horsetails and ferns, which have rhizoids but not true roots.

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Other Word Forms

Derived Forms

• thalloid
  adjective

Inflected Forms

Nouns

• thalli
  plural
• thalluses
  plural

Etymology

Origin of thallus

1820–30; < New Latin < Greek thallós young shoot, twig

Example Sentences

See Examples For:

thallus thalli

A slender stalk extends from the thallus, and an archegonial head sits at its top.

From Textbooks ● Jan. 1, 2015

In a bryophyte, all the conspicuous vegetative organs—including the photosynthetic leaf-like structures, the thallus, stem, and the rhizoid that anchors the plant to its substrate—belong to the haploid organism or gametophyte.

From Textbooks ● Jan. 1, 2015

The body of a lichen, referred to as a thallus, is formed of hyphae wrapped around the green partner.

From Textbooks ● Apr. 25, 2013

The photosynthetic organism provides carbon and energy in the form of carbohydrates and receives protection from the elements by the thallus of the fungal partner.

From Textbooks ● Apr. 25, 2013

Antheridia in an oval or obcordate disk immersed in the apex of the thallus.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Gray, Asa

Foliose species have lobed, leaflike bodies, or thalli; you can see both their upper and lower surfaces, which are different colors.

From Seattle Times ● Nov. 22, 2021

Fruticose lichens have thalli that are branch-, cup- or club-like, imparting the look of tiny shrubs.

From Seattle Times ● Nov. 22, 2021

The gametophytes grow as flat thalli on the soil with embedded gametangia.

From Textbooks ● Jan. 1, 2015

Spores disseminated by wind or water germinate into flattened thalli attached to the substrate by thin, single-celled filaments.

From Textbooks ● Jan. 1, 2015

These structures cannot then be produced from the product of a single spore nor even from the thalli derived from any two spores.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3 "Frost" to "Fyzabad" by Various