thallophyte /ˈθæləfaɪt/ noun1 •Any of very many primitive plants that consist of a thallus (plant body not differentiated into roots, stems and leaves), formerly collected in the obsolete taxonomic group Thallophyta.They lack the vascular tissues; thus, they are called thallophytes. Algae are thallophytes with chlorophyll. […] Fungi are thallophytes without chlorophyll. — 1994 formsthallophytes