GENERA OF GRASSES OF THE UNITED STATES. 137 



Eurasia. Some of the European species with a distinct palea have 

 been segregated as the genus Colobachne. 



Type species: Alopecurus pratensis L. 



Alopecurus L., Sp. PI. 60, 1753; Gen. PL, ed. 5, 30. 1754. Four species are 

 described, A. pratensis, A. geniculatus, A. hordciformis, and A. monspeliensis. 

 The third and fourth species do not agree with Linnseus's generic description 

 and are now referred, the third to Pennisetum and the fourth to Polypogon. 

 The other two were well known to Linnaeus and were described in his flora of 

 Sweden. The first, being an economic species, is chosen as the type species of 

 the genus. 



Alopecurus pratensis L. (fig. 74), meadow foxtail, is sometimes 

 used as a meadow grass in the eastern United States. It is recom 

 mended for mixtures on moist soil, being nutritious and producing 

 early forage. Meadow foxtail is an erect grass, 2 to 3 feet tall, with 

 short rhizomes, loose, often inflated, sheaths, and spikes or heads 2 

 to 4 inches long and about one-fourth of an inch thick. Introduced 

 from Europe, where it is favorably known as a meadow grass. 



Alopecurus geniculatus L. is a low, pale, soft grass, usually 6 to 18 

 inches high, with decumbent rooting bases and slender panicles 1 to 

 3 inches long and about one-eighth of an inch thick, the delicate awn 

 bent and protruding about twice the length of the spikelet. Found 

 in moist places across the continent. An allied and more common 

 species, A. aristulatus Michx. (A. geniculatus aristulatus (Michx.) 

 Torr.), is distinguished by the scarcely exserted awns. Alopecurus 

 alpinus J. E. Smith (A. occidentalis Scribn.), a northern species 

 extending into the Rocky Mountains of the United States, has a 

 short, thick spike with spikelets woolly all over. Alopecurus cali- 

 fornicus Vasey, of the northwestern Pacific coast region, has slender 

 spikes, 1 to 3 inches long and one- fourth of an inch thick, the spike- 

 lets 3 mm. long. The species of Alopecurus are all palatable and- 

 nutritious, but usually are not found in sufficient abundance to be of 

 great importance. 



62. POLYPOGON Desf. 



Spikelets 1-flowered, the pedicel disarticulating a short distance 

 below the glumes, leaving a short-pointed callus attached; glumes 

 equal, entire or 2-lobed, awned from the tip or from between the 

 lobes, the awn slender, straight ; lemma much shorter than the glumes, 

 hyaline, usually bearing a slender straight awn shorter than the 

 awns of the glumes. 



Annual or perennial usually decumbent grasses, with flat blades 

 and dense, bristly, spikelike panicles. Species about 10, in the tem- 

 perate regions of the world, chiefly in the Eastern Hemisphere, three 

 species being introductions into the United States. 



Type species : Alopecurus monspeliensis L. 



Polypogon Desf., Fl. Atlant. 1: 66. 1798. Only one species described, this 

 based on Alopecurus monspeliensis L. 



