Teucrium praepyrenaicum, sp. nov. (sect. Polium, Labiatae), a new species for the Spanish flora. A new species of Teucrium (sect. Polium, Labiatae) for the Iberian Peninsula flora is described and illustrated: T. praepyrenaicum, sp. nov., from the pre-Pyrenean mountains of Huesca province (Aragon, Spain). An illustration, a morphological description and the main diagnostic characters are presented.