GENUS 16. 



GRASS FAMILY. 



'33 



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



Paspalum distichum L. Syst. Nat. Ed. 10, 855. 17 59. 

 Digitaria paspaloides Michx. Fl. Bor. Am. i : 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, li'-s' 

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

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

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

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

 scales 5-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: Panicnm Crus-galli L. 



Sheaths glabrous. 



Spikelets 1^/2" long, the second and third scales more or less awned. i. E. Crus-galli. 



Spikelets i" long, the second and third scales merely awn-pointed. 2. E. 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, i'-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 i*" 

 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. 



