748 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



ennials, the pairs of racemes and their spathes more or less crowded, 

 forming a rather large elongate inflorescence. Type species, Hypar- 

 rhenia pseudocymbaria (Steud. ) Stapf . Name from Greek hypo, under, 

 and arren, masculine, alluding to the pair of staminate spikelets at the 

 base of the raceme. 



1. Hyparrhenia rufa (Nees) Stapf. (Fig. 1667.) Culms erect, 

 rather stout, 1 to 2.5 m tall; blades flat, elongate, 2 to 8 mm wide, 

 sometimes wider, very scabrous on the margins ; inflorescence 20 to 40 

 cm long, the pairs of racemes on long slender flexuous peduncles; 

 raoemes about 2 cm long, reddish brown, fertile spikelets mostly 5 to 7 

 in each raceme, 3 to 4 mm long, flattened from the back, pubescent 

 with dark-red hairs, the pedicels and rachis joints ciliate with red 

 hairs; awn 15 to 20 mm long, twice geniculate, twisted, red-brown, 

 hispidulous. 21 — Tropics of the Old World; introduced in tropical 



Figure 1667.— Hyparrhenia rufa, X 1. (Moldenke 243, Fla.) 



America; sparingly cultivated in Florida (where it has escaped) and 

 along the Gulf coast. Adapted to conditions in the regions mentioned, 

 but only moderately valuable as a forage grass. The native name in 

 Brazil is jaragua. 



Hyparrhenia hirta (L.) Stapf. Usually not more than 1 m tall; 

 blades usually less than 3 mm wide, more or less involute, flexuous; 

 racemes whitish or grayish silky-villous. % — Warmer parts ^ of 

 the Old World; cultivated at the Florida State Experiment Station 

 and probably elsewhere. Appears to have little forage value. 



147. SORGHUM Moench 



Spikelets in pairs, one sessile and fertile, the other pedicellate, 

 sterile but well developed, usually staminate, the terminal sessile 

 spikelet with two pedicellate spikelets. Tall or moderately tall 



