thallus

[ thal-uhs ]

noun

, Botany, Mycology.

, plural thal·li [thal, -ahy], thal·lus·es.

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

thallus

/ ˈθæləs /

noun

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

thallus

/ thăl′əs /

, Plural thalli thăl′ī

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.

Derived Forms

• ˈthalloid, adjective

Word History and Origins

Origin of thallus¹

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

Word History and Origins

Origin of thallus¹

C19: from Latin, from Greek thallos green shoot, from thallein to bloom

Example Sentences

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

From Seattle Times

The process of working out what things were often felt like trying to solve a recalcitrant crossword puzzle, particularly when it involved learning technical terms like scopulae and thalli.

From New York Times

Thallus without epidermis; capsule with a columella, short-pedicelled or sessile on the thallus.

From Project Gutenberg

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

From Project Gutenberg

Piece of thallus of a Sticta, with section, showing the immersed apothecia; the small openings of these dot the surface.

From Project Gutenberg