noun, plural thal·li [thal-ahy] /ˈθæl aɪ/, thal·lus·es. Botany, Mycology.
Origin of thallus
Examples from the Web for thallus
The colors of the Thallus and apothecia of Lichens—their causes, and the circumstances which modify and alter them.The Commercial Products of the Vegetable Kingdom|P. L. Simmonds
Another method is by the agency of little spores (zoospores) that are produced at the edges or extremities of the thallus.The Sea Shore|William S. Furneaux
Flowering plants cannot have directly arisen out of thallus plants, nor out of mosses; but only out of ferns, or Filicines.The History of Creation, Vol. II (of 2)|Ernst Haeckel
They are distinguished by possessing as gonidia algae foreign to the ordinary part of the thallus.
The thallus or body of the lichen is of very different form in different genera.