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 leaf-blades and terminal cylindric spikes. Spikelets 1-flowered, rarely 2-flowered, usually in 3's at each joint of the rachis, the lateral short-stalked and imperfect, rarely perfect; rachilla produced beyond the flower, the lower empty scales often reduced to awns and forming an apparent involucre around the spikelets. Empty scales rigid; flowering scales rounded on the back, 5-nerved at the apex, awned; palet scarcely shorter than the scale, 2-keeled. Stamens 3. Styles very short, distinct. Grain usually adherent to the scale, hairy at the summit. [Latin name for Barley.]
About 20 species, widely distributed in both hemispheres. Type species: Hordeum vulgare L.
Lateral spikelets abortive. | |||
Flowering scales, exclusive of awns, 3"-4" long. | |||
Awn of the flowering scale 1/2' long or less. | |||
All the empty scales of each cluster bristle-like. | 1. | H. | nodosum. |
Four of the empty scales of each cluster dilated above the base. | 2. | H. | pusillum. |
Awn of the flowering scale 1' long or more. | 3. | H. | jubatum. |
Flowering scales, exclusive of awns, about 6" long. | 4. | H. | murinum. |
Lateral spikelets with perfect flowers. | 5. | H. | Pammelii. |
Fig. 694
Hordeum nodosum L. Sp. PI. Ed. 2, 126. 1762. Hordeum pratense Huds. Fl. Angl. Ed. 2, 56. 1762.
Culms 6'-2° tall, erect, or sometimes decumbent, simple, smooth and glabrous. Sheaths shorter than the internodes; ligule 1/4" long, truncate; blades 1 1/2'-5' long, 1"-3' wide, flat, rough; spike 1'-3 1/2 in length; spikelets usually in 3's, the central one containing a palet and perfect flower, the lateral enclosing a staminate or rudimentary flower, or a palet only; empty scales of each cluster awn-like; flowering scale of the central spikelets 3"-4" long exclusive of the awn, which is 3"-6" long, the corresponding scale in the lateral spikelets much smaller and short-stalked.
In meadows and waste places, Indiana to Minnesota, Alaska, Texas and California. Also in Europe and Asia. June-July.
Fig. 695
Hordeum pusillum Nutt. Gen. 1: 87. 1818.
Culms 4'-15' tall, erect, or decumbent at the base, smooth and glabrous. Sheaths loose, usually shorter than the internodes, smooth and glabrous, the upper often enclosing the base of the spike; ligule very short; blades 1/2'-3' long, i"-2" wide, erect, smooth beneath, rough above; spike I-3' in length; spikelets usually in 3's, the central one containing a palet and perfect flower, the lateral imperfect; scales awned, the empty ones scabrous, those of the central spike-let and the lower ones of the lateral spikelets dilated above the base; flowering scale smooth, that of the central spikelet 3"-4" long, short-awned, the corresponding scale in the lateral spikelets smaller and very short-stalked.
In dry soil, Indiana to Tennessee, Wyoming, California, Texas and Louisiana; also sparingly introduced along the coast from Virginia to Florida. June-July.
 
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