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MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



slender. O — Weed, fields, waste 

 places, and open, mostly arid ground, 

 introduced from the Old World, 

 ballast, Mobile, Ala. ; adventive, Okla- 

 homa; Idaho and Washington; New 

 Mexico to California. Often difficult 

 to distinguish from the preceding. 



11. Hordeum vulgare L. Barley. 

 (Fig. 369.) Annual; culms erect, 60 

 to 120 cm. tall; blades flat, mostly 

 5 to 15 mm. wide, the auricle well 

 developed; spike erect or nearly so, 



2 to 10 cm. long, excluding awns, the 



3 spikelets sessile; glumes divergent 

 at base, narrow, nerveless, gradually 

 passing into a stout awn; awn of 

 lemma straight, erect, mostly 10 to 

 15 cm. long. O — Cultivated for 

 the grain, sometimes spontaneous in 

 fields and waste places but not per- 

 sistent. There are two groups of the 

 cultivated barleys. In the 2-rowed 

 forms (H. distichon L.) the lateral 



spikelets are fairly well developed but 

 sterile. The probable ancestor for at 

 least a part of these is H. spontaneum 

 Koch, of Asia. In the second group 

 all the spikelets produce large seed. 

 These are called 6-rowed (H. hexa- 

 stichon L.) or, if the lateral florets 

 overlap, 4-rowed barleys (in Euro- 

 pean literature). In some varieties 

 the caryopsis is naked. The ancestor 

 of the 6-rowed barleys is not known 

 but probably was similar to some of 

 our cultivated varieties of this group. 

 Hordeum vulgare var. trifurca- 

 tum (Schlecht.) Alefeld, beardless 

 barley. Awns suppressed or vari- 

 ously deformed, commonly 3-cleft, 

 the central division converted into a 

 hooded lobe. Adventive or occasional 

 in grainfields and along roads, Con- 

 necticut to New Jersey ; South Dakota, 

 Montana; Colorado, Utah, New Mex- 

 ico; California. 



50. LOLIUM L. Ryegrass 



Spikelets several-flowered, solitary, placed edgewise to the continuous 

 rachis, one edge fitting to the alternate concavities, the rachilla disarticulating 

 above the glumes and between the florets ; first glume wanting (except on the 

 terminal spikelet and rarely in 1 or 2 spikelets in a spike) , the second outward, 

 strongly 3- to 5-nerved, equaling or exceeding the second floret; lemmas round- 

 ed on the back, 5- to 7-nerved, obtuse, acute, or awned. Annuals or perennials, 

 with flat blades and slender, usually flat spikes. Type species, Lolium perenne. 

 Lolium, an old Latin name for darnel. 



Lolium perenne, perennial or English ryegrass, was the first meadow grass 

 to be cultivated in Europe as a distinct segregated species, the meadows and 

 pastures formerly being native species. This and L. ?nultiflorum, Italian rye- 

 grass, are probably the most important of the European forage grasses. Both 

 species are used in the United States to a limited extent for meadow, pasture, 

 and lawn. They are of importance in the South for winter forage. In the Eastern 

 States the ryegrasses are often sown in mixtures for parks or public grounds, 

 where a vigorous early growth is required. The young plants can be distin- 

 guished from bluegrass by the glossy dark-green foliage. L. temulentum, 

 darnel, is occasionally found as a weed in grainfields and waste places. It is 

 in bad repute, because of the presence in the grain of a narcotic poison, said 

 to be due to a fungus. Darnel is supposed to be the plant referred to as the 

 tares sown by the enemy in the parable of Scripture. 



Glume shorter than the spikelet. 



Lemmas nearly or quite awnless; culms subcompressed 1. L. perenne. 



Lemmas, at least the upper, awned; culms cylindric 2. L. multiflorum. 



Glume as long as or longer than the spikelet. Annuals. 

 Spike flat; spikelets much wider than the rachis. 



Florets plump, 6 to 8 mm. long 3. L. temulentum. 



Florets dorsally compressed, 9 to 10 mm. long 4. L. persicum. 



Spike subcylindric; spikelets scarcely wider than the rachis... 5. L. subulatum. 



