298 



CYPERACEAE. 



VOL. I. 



Spikelets iJ^"-2" long, the lower spreading. 

 Heads globose. 



Achene oblong or obovoid, about twice as long as thick. 

 Rachis wingless or very narrowly winged. 

 Heads globose. 

 Heads oblong. 

 Rachis-wings membranous, broad. 



Scales firm, not appressed ; spikelets loosely capitate. 

 Scales thin, closely appressed ; spikelets densely capitate. 



22. C. Torrcyi. 

 33. C. ovularis. 



34. C. filiciihnis. 



35. C. caye.nnensis. 



36. C. Grayi. 



37. C. globnlosiis. 



i. Cyperus flavescens L. Yellow Cyperus. 

 Galingale. Fig. 721. 



Cy perns flavescens L. Sp. PI. 46. i/53. 



Annual, culms very slender, tufted, leafy below, 

 3'-i2' tall, mostly longer than the leaves. Leaves 

 i"-ii" wide, smooth, the longer usually exceeding 

 the inflorescence; clusters terminal and sessile or on 

 1-4 short rays ; spikelets in 3's-6's, linear, subacute, 

 yellow, many-flowered, flat, 4"-p" long, ii"-2" broad; 

 scales ovate, obtuse, i-nerved, appressed, _twice as long 

 as the orbicular-ovate black obtuse lenticular shining 

 achene; stamens 3; style deeply 2-cleft, its branches 

 slightly exserted; superficial cells of the achene ob- 

 long. 



In marshy ground. New York to Michigan, Florida, 

 Mexico and Costa Rica. Also in the Old World, in Ber- 

 muda, Cuba and Dominica. Reported from Maine. 

 Aug.-Oct. 



2. Cyperus diandrus Torr. Low Cyperus. 

 Fig. 722. 



Cyperus diandrus Torr. Cat. PI. N. Y. 90. 1819. 

 Cyperus diandrus elongatus Britton, Bull. Torr. Club 

 19 : 226. 1892. 



Annual, culms tufted, slender, 2'-! 5' tall. Leaves 

 about i" wide, those of the involucre usually 3, the 

 longer much exceeding the spikelets ; clusters sessile 

 and terminal, or at the ends of 1-3 rays; spikelets 

 4"-9" long, linear-oblong, acute, flat, many-flowered ; 

 scales ovate, green, brown, or with brown margins, 

 obtuse, i -nerved, appressed, membranous, dull ; 

 stamens 2 or 3; style 2-cleft, its branches much ex- 

 serted; achene lenticular, oblong, subacute, gray, 

 not shining, one-half as long as the scale, its super- 

 ficial cells quadrate, about as long as wide. 



In marshy places, New Brunswick to Minnesota, south 

 to South Carolina and Kansas. Cypress-grass. Galin- 

 gale or Galangal. Aug.-Oct. 



3. Cyperus rivularis Kunth. Shining Cyperus. 



Fig. 723. 



Cyperus rivularis Kunth, Enum. 2 : 6. 1837. 

 Cyperus diandrus var. ( ?) castancus Torr. Ann. Lye. N. Y. 

 3: 252. 1836. Not C. castaneus Willd. 1798. 



Similar to the preceding species, culms slender, 

 tufted, 4'-: 5' tall. Umbel usually^ simple; spikelets 

 linear or linear-oblong, acutish, 4"-io"_ long; scales 

 green or dark brown or with brown margins, appressed, 

 firm, subcoriaceons, shining, obtuse; stamens mostly 3; 

 style 2-cleft, scarcely exserted; achene oblong or 

 oblong-obovate, lenticular, somewhat pointed, dull, its 

 superficial cells quadrate. 



In wet soil, especially along streams and ponds, Maine to 

 southern Ontario and Michigan, south to Missouri, North 

 Carolina and Kansas. Aug.-Oct. 



