TRISTECJINE.E. 



75 



any cluster fertile, others sterile, spikelets finely pubescent, with a 

 sheath of very short hairs at the base, linear-lanceolate, 5 mm, lon<^ 

 third glume elliptical-lanceolate, 5-nerved, as long as the spikelet, 

 witli a straight awn about half its own length : jialea ellii)tical when 

 spread, 5 mm. long, with % nerves near the middle. Grain linear, 

 compressed, 1 mm. long. 

 Mexico, Schaffner 1070. 



Fio. Wi.—Scluiffiura oriteiUa. A spikcl.'t dissoctod. (Scribnor.) 



'riuiii; IV.— TRISTEGINE^. 



Spikek'ts all simihir. 1 "i-llowered, in paniclfd racemes. fallin<T 



olT singly from the nltitiiiite l)ran('hes of the continuous axis of (ho 



panicle. iMiipt.y glumes three, herbaceous or chartaceou.^, the first 



