The intergeneric hybrid grass "Poa labradorica"

The new nothogenus × Dupoa (Dupontia × Poa ) is published. Nomenclature of the only known nothospecies, × Dupoa labradorica (= Poa labradorica ), is discussed. Morphology and synecology of this poorly known arctic and subarctic grass are described and a key to related taxa is given. Its morphology and ecology overlap with the putative parental taxa, Poa eminens and Dupontia fisheri ssp. psilosantha . Establishment and persistence of this sterile hybrid are related primarily to geological processes associated with glacio-eustatic rebound and seasonal ice action affecting its seashore habitats.