Genus 16. 



GRASS FAMILY. 



133 



20. Paspalum distichum L. Joint-grass. Fig. 307. 



Paspalum distichum L. Syst. Nat. Ed. 10, 855. 1759. 

 Digitaria paspaloides Michx. Fl. Bor. Am. 1 : 46. 1803. 

 Paspalum Michauxianum Kunth, Rev. Gram. 25. 1829. 



Culms erect, 4/-2 tall, extensively creeping at the 

 base. Sheats smooth, sometimes ciliate on the 

 margins, or sparsely pubescent; blades flat, ii'-s' 

 long, i"-3" wide, acuminate, smooth; racemes 1'- 

 2i' long, in pairs, or occasionally with a third, the 

 rachis flat, 4"-i" wide, smooth; spikelets ii"-ii" 

 long, ovate, acute, nearly sessile in 2 rows, the outer 

 scales S-nerved, the first glabrous, the second ap- 

 pressed-pubescent, the acute third sparingly bearded 

 at the apex. 



On the seashore or along rivers, Virginia to Mis- 

 souri, California and Washington, south to Florida, 

 Texas and Mexico. Also in tropical America. Aug.- 

 Sept. Knot-grass. Devil's-grass. Seaside-millet. 



16. ECHINOCHLOA Beauv. Agrost. 53. 1812. 



Usually tall grasses, commonly annuals, with broad leaf-blades, and a terminal inflores- 

 cence consisting of i-sided racemes. Spikelets i-flowered, singly disposed, or in smaller 

 racemes or clusters on the ultimate divisions of the inflorescence. Scales 4, the outer 3 

 membranous, hispid on the nerves, the third and usually also the second scale awned or awn- 

 pointed, the awn often very long, the fourth scale indurated at maturity, shining, pointed, 

 the margins thick and inrolled, enclosing a palet of similar texture, which is free at the tip, 

 and a perfect flower. Stamens 3. Styles distinct. Stigmas plumose. [Greek, in reference 

 to the hispid hairs of the spikelets.] 



Species about 12, mostly in warm and tropical regions. Type species : Panicum Crus-galli L. 



Sheaths glabrous. 



Spikelets iyi" long, the second and third scales more or less awned. 1. jE. Crus-galli. 



Spikelets 1" long, the second and third scales merely awn-pointed. 2. B. colona. 



Sheaths, at least the lower ones, densely papillose-hirsute. 3. E. Walteri. 



i. Echinochloa Crus-galli (L.) Beauv. Barnyard-grass. Cockspur-grass. 



Barn-grass. Water-grass. Fig. 308. 



Panicum Crus-galli L. Sp. PI. 56. 1753. 

 Echinochloa Crus-galli Beauv. Agrost. 161. 1812. 



Culms 2°-4° tall, often branching at base. Sheaths 

 smooth and glabrous; blades 6'-2° long, l'-i' wide, 

 glabrous, smooth or scabrous ; panicle composed of 

 5-15 sessile erect or ascending branches, or the lower 

 branches spreading or reflexed ; spikelets ovate, green 

 or purple, densely crowded in 2-4 rows on one side 

 of the rachis ; second and third scales about ii" 

 long, scabrous or hispid, the third scale more or less 

 awned, empty, the fourth ovate, abruptly pointed. 



In cultivated and waste places, throughout North 

 America except the extreme north. Widely distrib- 

 uted as a weed in all cultivated regions. Naturalized 

 from Europe. Aug.-Oct. Loose panic-grass. 



