Abstract
The new species Chiococca grandiflora Lorence & T.Van Devender from Sinaloa and Sonora, Mexico differs from its congeners by its larger, showy white flowers in compact cymes of 3-9, and infundibuliform corollas 16-20 mm long with tubes 13-17 mm long and lobes 3-3.5 mm long. Its distribution, habitat, and relationships are outlined. The conservation status for this species is estimated to be Endangered (EN) based on IUCN Red List Criteria.