772 



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



Cymbopogon nardus (L.) Rendle, 

 citronella grass, nard grass, in which 

 the first glume of the sessile spikelet 

 is flat on the back and, C. citratus 

 (DC.) Stapf, lemon grass, in which 

 the first glume is concave on the 

 back. These species are sometimes 

 cultivated in gardens in southern 

 Florida and southern California but 

 do not flower there. Name from 

 Greek kwnbe, boat, and pogon, beard, 

 alluding to the boat-shaped spathes. 



VETIVERIA Bory 



Vetiveria zizanioides (L.) Nash. 



Vetiver. (Fig. 1175.) Robust densely 

 tufted perennial with simple culms 

 and large erect panicles, the slender 

 whorled branches ascending, naked 

 at base, the awnless spikelets muri- 

 cate. Also called khus-khus and khas- 

 khas. % —Native of the Old 

 World, frequently cultivated in trop- 

 ical America for hedges and for the 

 aromatic roots, these being used for 

 making screens and mats which are 

 fragrant when wet. Vetiver oil is 

 much used in perfumery. Escaped 



from cultivation in Louisiana. Name 

 from vettiver, the native Tamil name. 



155. HYPARRHENIA Anderss. 

 ex Stapf 



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 (keeled toward 

 the summit in Hyparrhenia rufa), 

 the base usually elongate into a 

 sharp callus, the fertile lemma with 

 a strong geniculate awn; sterile spike- 

 lets 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 elongate inflorescence. Type 

 species, Hyparrhenia 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. 1176.) Culms erect, rather 

 stout, 1 to 2.5 m. tall; blades flat, 



Figuee 1176. — Hyparrhenia rufa, X 1. 

 (Moldenke 243, Fla.) 



