This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Annual or perennial grasses, with flat or involute leaf-blades and terminal spikes. Spike-lets 3-many-flowered, sessile, single and alternate at each notch of the usually continuous rachis, the side of the spikelet turned toward the rachis. Two lower scales empty; flowering scales rigid, rounded on the back, 5-7-nerved, usually acute or awned at the apex; palets 2-keeled, the keels often ciliate. Stamens 3. Styles very short, distinct. Stigmas plumose. Grain pubescent at the apex, usually adherent to the palet. [Greek, referring to the growth of these grasses in wheat fields.]
Culms not densely tufted; plants with creeping rootstocks or stolons.
Spikelets glabrous or hispidulous.
Empty scales strongly 5-11 -nerved.
Empty scales attenuate into an awn or awn-point; plant green.
Under surface of the leaf-blades smooth, the upper surface often pubescent; an
Under surface of leaf-blades very rough, the upper surface glabrous; a western grass.
Empty scales rather abruptly narrowed to a blunt point; plant glaucous.
Empty scales usually faintly 1-3-nerved, sometimes 5-nerved.
Spikelets densely pubescent.
Culms densely tufted; plants with no rootstocks or stolons.
Awn shorter than the flowering scale.
Empty scales broad above the middle.
Empty scales narrowed from below the middle.
Awn much longer than the flowering scale.
Triticum repens L. Sp. PI. 86. 1753. Agropyron repens Beauv. Agrost. 146. 1812.
Culms 1 -4 tall, from a long jointed running root-stock. Sheaths usually shorter than the internodes, smooth and glabrous; ligule very short; blades 3'-12' long, 1"-5" wide, smooth beneath, rough above; spike 2'-8' in length, strict; spikelets 3-7-flowered; empty scales strongly 5-7-nerved, usually acute or awn-pointed, sometimes obtuse; flowering scales smooth and glabrous, acute or short-awned at the apex.
In fields and waste places, almost throughout North America except the extreme north. Naturalized from Europe and often a troublesome weed. Very variable. Native also of Asia. Quitch-, Twitch-, or Witch-grass. Stroil. Quichens. Squitch. Wickens. Shelly-, Knot-, Dog-, Shear- or Quack-grass. Blue-joint. Slough- or Pond-grass. False Wheat. Colorado blue-grass. July-Sept.