494 MISC. PUBLICATION 2 0, U. S. DEPT. OF AGRICULTURE 



1-nervecl, the second about as long as the lemmas, firm, 3- to 4-nerved, 

 bearing on the back a strong divergent awn ; lemmas rather papery, 3- 



nerved, with long hairs on the lat- 

 eral nerves and a short straight 

 or curved awn on the back just 

 below the apex, the first and 

 second lemmas empty, the third 

 enclosing a perfect flower, the 

 upper 1 to 3 empty and succes- 

 sively smaller. Erect, slender, 

 rather tall perennials, with us- 

 ually solitary, often curved 

 spikes. Type species, Ctenium 

 carolinianum Panz. (C. aro- 

 maticum). Name from Greek 

 ktenion, a little comb, alluding 

 to the pectinate arrangement of 

 the spikelets. 



Plants forming dense tussocks ; second 

 glume with a row of prominent 

 glands on each side of the mid- 

 nerve ; awn stout, at maturity 

 horizontal or nearly so ; ligule 

 about 1 mm long 



1. C. AROMATTCUM. 



Plants with slender scaly rhizomes; 

 second glume glandless or with 

 obscure glands ; awn rather slen- 

 der, not horizontally spreading; 

 ligule 2 to 3 mm long 



2. C. FLORIDANUM. 



1. Ctenium aromaticum 

 (Walt.) Wood. Toothache 

 grass. (Fig. 1052.) Culms 1 

 to 1.5 m tall, the old sheaths per- 

 sistent and fibrillose at base; 

 ligule about lmm long; blades 

 flat or involute, stiff; spike 5 to 

 15 cm long; spikelets 5 to 7 mm 



long. Q[ (Ctenium carolinianum Panz.) — Wet pine barrens, Coastal 



Plain, Virginia to Florida and Louisiana (fig. 



1053). The roots spicy when freshly dug. 



Furnishes fair cattle forage in moist pine bar- 

 rens of Florida. 

 2. Ctenium floridanum (Hitchc.) Hitchc. 



(Fig. 1054.) Differs from C. aromaticum in 



having creeping scaly rhizomes, ligule 2 to 3 



mm long, second glumes with longer, more 



slender awns and without glands or with only 



obscure ones. % (Erroneously referred by American authors to 



Campulosus chapadensis Trin.) — Moist pine barrens, Florida. 



Figure 1050. — Spartina patens. Panicle, 

 1 ; spikelet, X 5. (Killip 6359, Md.) 



Figure 1051. — Distribution 

 of Spartina patens. 



