GENUS i. 



YELLOW-EYED GRASS FAMILY. 



451 



Lateral sepals nearly entire ; heads narrowly ovoid, acute during anthesis. 



2. X. montana. 



Lateral sepals toothed ; heads broadly ovoid, obtuse. 3. X. caroliniana. 



Leaves broadest at the middle. 4. X. communis. ' 



Heads oblong or nearly cylindric ; bracts numerous, in many series. 5. X. elata. 



Lateral sepals longer than the bracts, exserted, their keels fimbriate or erose-lacerate. 



Keels of the lateral sepals erose-lacerate ; heads not plumose. 6. X. Congdoni. 



Keels of the lateral sepals long-fimbriate ; heads somewhat plumose. 7. X. fimbriata.' 



Plants conspicuously bulbous-thickened at the base; leaves spirally twisted. 8. X.arenicola. 



i. Xyris flexuosa Muhl. Slender Yellow-eyed 

 Grass. Fig. 1132. 



Xyris flexuosa Muhl. Cat. 5. 1813. 



Xyris tort a J. E. Smith, in Rees' Cyclop. 1818. 



Scapes slender, straight or sometimes slightly twisted, 

 4'-i8' tall, 2-edged above, bulbous-thickened at the base. 

 Leaves narrowly linear, flat or becoming twisted when 

 old, i'-6' long, i"-ii" wide; head globose, or short- 

 oblong, obtuse, 3"~4" high ; bracts broadly oval or 

 slightly obovate, entire or somewhat lacerate at the 

 apex; lateral sepals linear, about as long as the bracts, 

 curved, finely fringed with short hairs on the wingless 

 keel ; expanded flowers $"-4" broad. 



In swamps and bogs, Maine to Minnesota, south to 

 Georgia, Missouri and Texas. Yellow flowering-rush. July- 

 Sept. 



2. Xyris montana H. Ries. Northern Yellow- 

 eyed Grass. Fig. 1133. 



Xyris flexuosa var. pusilla A. Gray, Man. Ed. 5, 548. 



1867. Not X. pusilla R. Br. 1810. 

 Xyris montana H. Ries, Bull. Torr. Club 19: 38. 1892. 



Scapes very slender, straight or slightly twisted, 

 2-edged above, 2'-i2' tall, not bulbous-thickened at 

 the base. Leaves narrowly linear, i'-6' long, \"-\" 

 wide, not at all twisted or but very slightly so ; head 

 ovoid, acute during anthesis, or narrowly subacute, 

 ii"-3" long; bracts oval or obovate, rounded and 

 finely lacerate at the apex ; lateral sepals linear, ir- 

 regularly erose on the winged keel near the apex, 

 about as long as the bracts. 



In bogs, Nova Scotia to Ontario and Michigan, south 

 to the Pocono Mountains of Pennsylvania. July-Aug. 



3. Xyris caroliniana Walt. Carolina Yellow- 

 eyed Grass. Fig. 1134. 



Xyris caroliniana Walt. Fl. Car. 69. 1788. 

 Xyris Jupacai Michx. Fl. Bor. Am. i : 23. 1803. 



Scapes mostly slender, straight or somewhat 

 twisted, 2-edged above, i-2 tall, not thickened at 

 the base. Leaves linear, flat, 4'-i5' long, i"-5" 

 wide ; head broadly ovoid, blunt, 4"-8" long ; scales 

 oval or slightly obovate, entire or somewhat lacerate; 

 lateral sepals linear, about as long as the bracts, the 

 narrowly winged keel serrate only above the middle. 



In swamps and bogs, Maine and Massachusetts to 

 Pennsylvania, Florida and Louisiana, mostly near the 

 .coast. Young states of this plant may be mistaken for 

 X. montana. June-Aug. 



