Dupontia

Plants perennial; rhizomatous. Culms 5-80 cm. Sheaths closed for 1/2 - 2/3 their length, glabrous; auricles absent; ligules membranous, glabrous, truncate; blades flat or folded, usually glabrous, adaxial surfaces sometimes scabrous or shortly pubescent. Inflorescences panicles, diffuse to dense and spikelike, with few spikelets; branches 0.7-3.5(8.5) cm, smooth, stiff, erect to reflexed, secondary branches usually appressed. Spikelets pedicellate, slightly laterally compressed, with 1-4(5) florets, distal florets sterile; rachillas prolonged beyond the uppermost floret or terminating in a vestigial floret, glabrous; disarticulation above the glumes and beneath the fertile florets. Glumes subequal, equaling or usually exceeding the distal florets, ovate and obtuse to lanceolate-attenuate, membranous, glabrous, 1-3-veined, unawned; calluses short, blunt, with a ring of stiff hairs, hairs to about 1 mm; lemmas ovate to ovate-lanceolate, membranous to coriaceous, glabrous or pubescent, with 3(5) fine veins, apices acute to acuminate, midveins sometimes excurrent as a mucro or awn to 1(2.2) mm; paleas shorter than the lemmas, glabrous, sometimes scabrous on the veins; lodicules 2, membranous, glabrous; anthers 3; ovaries glabrous. Caryopses shorter than the lemmas, concealed at maturity, falling free of the lemma and palea; hila 1/6 – 1/3 the length of the caryopses, ovate, x = not clear, 7 or 11.

Distribution

Greenland, Nfld. And Labr. (Nfld.), Man., N.W.T., Nunavut, Ont., Que., Yukon, Alaska

Discussion

Dupontia is a monotypic genus of arctic and subarctic wetlands, found throughout the holarctic region except in Scandinavia. Hybrids with Arctophila are referred to xArctodupontia (see next); hybrids with Poa eminens are referred to xDupoa (see previous).

Selected References

Brysting, A.K., S.G. Aiken, L.P. Lefkovitch, and R.L. Boles. 2003. Dupontia (Poaceae) in North America. Canad. J. Bot. 81:769-779

Brysting, A.K., M.F. Fay, I.J. Leitch, and S.G. Aiken. 2004. One or more species in the arctic grass genus Dupontia?—A contribution to the Panarctic Flora project. Taxon 53:365-382

Jurtsev, B.A. 1995. Dupontia. Pp. 224-229 in J.G. Packer (ed., English edition). Flora of the Russian Arctic, vol. 1, trans. G.C.D. Griffiths. University of Alberta Press, Edmonton, Alberta, Canada. 330 pp. [English translation of A.I. Tolmachev (ed.). 1964. Arkticheskaya Flora SSSR, vol. 2. Nauka, Leningrad [St. Petersburg], Russia. 272 pp.].

Lower Taxa

Dupontia fisheri