The asexual spores, which are not motile, are formed in some of the surface cells of the thallus.
The colouring matter is ready formed and abundant in the thallus.
Piece of thallus of Parmelia conspersa, with section through an apothecium.
The thallus does not yet show this important morphological division.
In the first process, portions of thallus containing gonidia may be accidentally separated and so may start new plants.
The structure of the thallus may serve to represent that of most of the Lichens.
Near the margins of the lobes of the thallus are small dark points.
Antheridia immersed in the thallus, covered with dentate scales.
The necks of the archegonia hardly project above the general surface of the thallus.
Capsules immersed in the thallus or sessile upon it, indehiscent.
Latin, from Greek thallos "green shoot, twig," related to thalia "abundance," thalos "scion, child," ultimately from PIE root *dhal- "to bloom" (cf. Old Irish duilesc, a type of algae).
thallus thal·lus (thāl'əs)
n. pl. thal·lus·es or thal·li (thāl'ī)
A plant body or fungus undifferentiated into stem, root, or leaf.
Plural thalli (thāl'ī)
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.