Definition of thallophyte in US English:



  • A plant that consists of a thallus.

    • ‘The dark phosphate bed of Weng'an contains a well-preserved, diverse floral assemblage including multicellular thallophytes, acritarchs, and cyanophytes.’
    • ‘The plant form of the thallophytes is an undifferentiated thallus lacking true roots, stems, and leaves.’
    • ‘Classification of this group of thallophytes is based on characteristics such as types of photosynthetic pigments present, the kind of reserve products found in the cells and the types of reproductive patterns.’
    • ‘Besides the ordinary algæ and fungi the thallophytes contain many forms which are not classified easily, as slime-moulds, bacteria, diatoms etc.’
    • ‘From the mid 17th century, the meaning changed to that now current, by which yeast refers to a single-celled plant, a thallophyte and one of the lowest members of the vegetable kingdom along with algae, lichens, and fungi.’
    • ‘Many of the thallophytes, bryophytes and pteridophytes are found here exclusively because of the special topographical and climatic features of the locality, and are not to be found for hundreds of kilometres around in other areas.’


Mid 19th century: from modern Latin Thallophyta (former taxon), from Greek thallos (see thallus) + -phyte.