Dyes derived by condensation of phthalic anhydride with resorcinol (and derivatives) or m
-aminophenol (and derivatives), of which fluorescein is the prototype (all such dyes have the xanthene nucleus).
See also: phthaleins, rhodamine dyes
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1374 (https://doi.org/10.1351/pac199567081307)