Calamovilfa longifolia var. magna
Sheaths usually pubescent, often densely so, rarely glabrous. Panicles to 77.5 cm long, usually 1.3-5.5 times as long as wide; branches to 33 cm long, typically widely divergent, sometimes reflexed in the lower 1/3 of the panicle. Spikelets commonly with a brownish cast, relatively loosely imbricate.
Ill., Ind., Ont., Ohio, Mich., Wis., N.Y., Pa., Iowa
Calamovilfa longifolia var. magna grows on dunes and sandy shores around lakes Superior, Michigan and Huron, with outlying stations in sand or sandy soils.
"decumbent" is not a number.