Plants perennial; rhizomatous. Culms 25-80 cm, glabrous, often glaucous, with 2-4 nodes. Sheaths closed for 1/3-2/3 of their length, glabrous, not conspicuously glaucous; ligules membranous, whitish- or yellowish-brown, acute to obtuse, lacerate to erose, ciliate; blades glabrous. Inflorescences panicles. Spikelets with (1)2-3(4) florets. Glumes usually not surpassing the florets, glabrous, often glaucous, acute to acuminate; calluses bearded, hairs often crinkled below the keel and/or absent from the sides; lemmas usually scabrous, sometimes smooth towards the base, acute; paleas smooth or slightly scabrous; anthers 3, indehiscent. Caryopses absent.

×Dupoa is a sterile hybrid between Dupontia and Poa. Only one species is known.

1.   ×Dupoa labradorica (Steudel) J. Cay. & Darbysh.
Labrador Bluegrass, Pâturin du Labrador

Rhizomes to 1.5 mm thick, nodes with few roots. Culms 25-80 cm. Ligules 1-4 mm; blades 5-20 cm long, 2-6 mm wide. Panicles 8-20 cm, open to somewhat dense; branches glabrous, with spikelets to the base. Spikelets 5-10 mm. Glumes subequal to unequal; lower glumes 4-8.5 mm, 1-3-veined; upper glumes 6.5-10 mm, (1)3-veined; lemmas 4-7 mm, 3-5-veined; paleas 4-6 mm; anthers 1.8-2.5 mm. 2n = 43-46 (43+0-3).

×Dupoa labradorica is known from southeastern Hudson Bay, eastern James Bay, and northern Labrador. Its distribution is completely within the sympatric range of the parental species. Additional records are to be expected from regions where both parental species are found, such as Alaska and the Russian Far East. It grows on seashores, lagoon margins, and salt marshes, usually in relatively deep organic matter over clay layers sometimes mixed with sandy or gravelly deposits, sometimes in dense and almost pure stands. Occurrence and spread of ×Dupoa labradorica are related primarily to geological processes associated with glacio-eustatic rebound and seasonal ice action affecting its seashore habitats.

×Dupoa labradorica is a sterile hybrid between Dupontia fisheri and Poa eminens. It is similar to Poa eminens but has narrower leaves, stems, and rhizomes, and more open panicles. It differs from Dupontia fisheri in having glumes that usually do not surpass the florets, and some wooly or crinkly callus hairs. It differs from both parental species in having indehiscent anthers and no caryopses.