Isotheca

{{Short description|Genus of flowering plants}}

{{Speciesbox

| genus = Isotheca

| parent_authority = Turrill (1922)

| species = alba

| authority = Turrill (1922)

}}

Isotheca is a monotypic genus of flowering plants belonging to the family Acanthaceae. The only species is Isotheca alba. It is a subshrub native to Mount Aripo on Trinidad and to northeastern Venezuela.{{cite web |title=Isotheca Turrill {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:668-1 |website=Plants of the World Online |access-date=3 February 2024|language=en}}