404 MISC. PUBLICATION 243, U.S. DEPT. OF AGRICULTURE 
toward the tip, the midrib rather stout below, whitish on the upper 
side; inflorescence 30 to 60 cm long, nodding (fig. 358). 
é SpernEly escaped from cultivation. Called “hierba de limon” in 
uba. 
FIGURE 358.—Cymbopogon citratus. Branchlet, X 1 (Sintenis 5295). 
2. Cymbopogon nardus (L.) Rendle, Cat. Afr. Pl. Welw. 2: 155. 1899. 
CITRONELLA GRASS. 
Andropogon nardus L., Sp. Pl. 1046. 1753. India. 
Similar to C. citratus in habit, differing in the concave glumes of the 
sessile spikelet. In Puerto Rico the fibrous rootstock is used as a 
toothbrush by the poorer people. 
109. HYPARRHENIA Anderss.; Stapf, in Prain, Fl. Trop. 
Africa 9: 291. 1918 
Spikelets in pairs, as in Andropogon, but spikelets of the lower pairs 
alike, sterile, and awnless; fertile spikelets 1 to few in each raceme, 
terete or flattened on the back, the margins of the first glume rounded, 
not sharply inflexed nor keeled (keeled toward the summit in H. rufa), 
the base usually elongate into a sharp callus, the fertile lemma with a 
strong geniculate awn; sterile spikelets awnless; racemes in pairs, on 
slender peduncles, and subtended by a spathe. Tall perennials, the 
pairs of racemes and their spathes more or less crowded, forming a 
rather large inflorescence at the upper part of the plant. 
Spikelets nearly glabrous or rather sparsely hirsute; pubescence usually rufous. 
H. RUFA. 
Spikelets densely villous; pubescence whitish______._____------- 2. Sara 
1. Hyparrhenia rufa (Nees) Stapf, in Prain, Fl. Trop. Afr. 9: 304. 
1918. 
Trachypogon rufus Nees, Agrost. Bras. 345. 1829. Brazil. 
Andropogon rufus Kunth, Rév. Gram. 1: Sup. XXXIX. 1830. 
Cymbopogon rufus Rendle, Cat. Afr. Pl. Welw. 2: 155. 1899. 
