114 PANICACE.E. 



acute, 1-3 mm. long. 3-nerved, second 5-nerved, third or floral 

 glume to the neuter floret like the second empty glume ; palea as long 

 as its glume, oval, hyaline ; fertile floret rugose, oval, mucronate. 



Mexico, Pringle 375, Palmer 254. 



Found in Mexico, West Indies, Egypt, and India, and very like- 

 ly in Texas and New Mexico. 



13. P. Isachne Koth, Nov. PI. 8p. 54 (1821). Var. Mexicana 

 (Vasey). P. eruciforme Sibth. Fl. Gra^c. 1 : 44, t. 59 (1806). 

 Var. Mexicana Vasey, ined. 



Culms branching, creeping below, nodes hairy, 20-40 cm. high. 

 Leaf-blades flat, rough, broad at the base, sometimes hairy, 5-10 

 cm. long, 3-7 mm. wide. Panicle secund, narrow, 6-12 cm. long, 

 sometimes partially included. Spikes 8-12, alternate, 1-2 cm. 

 long, rachis filiform. Spikelets single, alternate, imbricate for 

 half their lengtli on pedicels less than 1 mm. long, attached to one 

 side of the rachis, pubescent, elliptical, almost acute, 1.7 mm. long, 

 first glume broad, minute, second ovate, obtuse, 5-nerved, as also 

 is the floral glume of the neuter floret, its palea obtuse, shorter; 

 fertile floret smooth, about 1.5 mm. long. 



Specimen seen was cultivated from seed obtained in Mexico, by 

 U. S. Dept. Agricul., 1887. 



14. P. paspaloides Pers. Syn. 1:81 (1805). 



An erect stout glabrous perennial, sparingly branched, 60-90 

 cm. high. Leaf-blades 20-30 cm. long, 6 mm. wide. Spikes 

 10-20, erect, simple, alternate along 2-3 centimeters of the axis. 

 2-3 cm. long. Spikelets single, subsessile on two sides of a 

 flexuous, triangular rachis, those in one row overlapping for one- 

 fourth their length, glabrous, doubly convex, oval, acute, awnless, 

 2.5 mm. long, containing a staminate and a perfect flower; first 

 and second empty glumes membranous, broad, obtuse, the former 

 nerveless, 0.5 mm. long, the latter twice as long, 4-nerved; floral 

 glume of the lower floret 5-nerved ; palea as long, hyaline, obtuse, 

 second floret oval. 



Mexico, Palmer AV.). 690, P r i nfile 'A'.V^^^ \ Texas, Xealleij. 



In water, Florida to Texas and Mexico; also found in Central 

 America, Mauritius, Brazil, Egypt, tropical Africa, and East Indies. 



