CREEPING FOXTAIL--Alopecurus arundinaceus
Comments:  Creeping foxtail, Alopecrurus arundinaceous, closely resembles timothy in appearance, origin, and use.  In contrast to timothy, creeping foxtail flowers very early (May), and its panicles blacken upon maturity, normally shattering by late June.  Spikelets are softly hairy and fluffy.  It is well adapted to soils normally too wet to cultivate.  With irrigation and fertilizer, production and regrowth are excellent.  Creeping foxtail is used in South Dakota to seed seasonally wet depressions.
Picture and information can be found on pages 52 and 53 of Grassland Plants of South Dakota and the Northern Great Plains, by James R. Johnson and Gary E. Larson.  Published in 1999 by South Dakota State University, Brookings, SD.