226 



CYPERACE^E. 



Carex. 



23. 



24. 



25. 



28. 



Spike globose, straw-colored, of 5 to 20 spikelets : bracts expanded 

 at base, longer than the stem : perigynium ovate-lanceo- 

 late, spongy at base. 



Spike variegated, chestnut and green, subglobose, of 3 to 8 rather 

 large spikelets : perigyuium broadly ovate or orbicular, 

 abruptly attenuate to a sharp minutely bidentate beak, 

 broadly winged to the base, exceeding the scale. 

 Spikelets distinct. 

 Spikelets male at top. 



Spike linear-oblong, of 4 to 7 contiguous sessile spikelets : peri- 

 gynium obovate, attenuate to the base and to the obliquely 

 cut entire beak, nerveless, about as long as the broadly 

 ovate mucrouate scale. 



Spikelets 2 to 6, remote, 2 - 6-flowered: perigynium oblong, bicon- 

 vex, abruptly minutely beaked, closely striate-uerved, cori- 

 aceous, longer than the scale. 

 Spikelets male at bottom. 



Spikelets 3 to 10, ellipsoidal, remote : perigynium ovate, abruptly 

 short-beaked, many-nerved, spongy at base. 



Spikelets 3 to 10 : perigynium lanceolate,. acuminate, rostrate, 



spongy at base, exceeding the 1 - 3-nerved scale. 26. 



Spikelets 4 to 8, polygamous : perigynium ovate from a cordate 

 sharp-margined base, nerved, sharply toothed, divergent, 

 equalling the scale. 



Spikelets 3 or 4, round : perigynium ovate-lanceolate from a round 

 or ovate spongy base, rostrate, squarrose spreading, twice 

 as long as the scale. 



Spikelets pale, 8 to 10, ellipsoidal, 8 to 14 lines long: perigynium 



lanceolate, acuminate, rostrate, twice as long as the scale. 29. 



Spike fulvous, ovoid or oblong, of 8 to 12 crowded or contiguous 

 spikelets : perigynium narrowly lanceolate, attenuate, ros- 

 trate, longer than the scale. 



Spikelets numerous, pale, ellipsoidal, obovoid, crowded or con- 

 tiguous : perigynium elliptical, gradually beaked, longer 

 than the scale. 



Spike oblong, of 7 to 1 or more ellipsoidal contiguous spikelets : 



perigynium ovate, winged to the base, exceeding the scale. 32. 



Spike oblong, of 4 to 10 round or obovoid spikelets, the lower 

 subremote : perigynium ovate or orbicular, strongly nerved, 

 equalling the scale : nutlet orbicular, large. 



# * * Uppermost spikelet male at base ; the rest female : stigmas 3. 

 Perigynium granular, obscurely nerved, the oriiice entire or emargi- 



nate, shorter than the scale. 



Perigynium not granular, nerved, bidentate : scales shorter. 

 Perigynium compressed above, triangular below, nerveless. 

 Perigynium nerveless, except 2 intramarginal nerves and 2 short 



nerves diverging from the base of the beak. 



* * * * Spikelets unisexual ; the upper male, mostly single ; the rest 



female or sparingly androgynous. 

 Stigmas 2. 



Perigynium beakless, globose or pear-shaped, coriaceous, strongly 



nerved. 

 Perigynium short-beaked. 



Very slender : spikelets rather loose : perigynium ovate, tapering 

 to an entire truncate orifice, not winged, obscurely nerved : 

 nutlet abruptly prolonged into the curved cylindrical style. 39. 

 Perigynium round-obovate or ovate, nerveless, abruptly beaked, 



orifice entire or emarginate : sheaths entire : stigmas 2 or 3. 40. 

 Perigynium oval, rostellate with entire, orifice, stipitate, papil- 

 lose, strongly nerved, deciduous : nutlet globose. 

 Male spikelet sometimes female below: perigynium elliptical, com- 

 pressed and empty above, with the beak entire, plano- 

 convex below, delicately nerved, resinously dotted, very 

 deciduous : sheaths fibrous-reticulate. 



Male spikelets 1 to 4, the female 2 to 5 : perigynium elliptical or 

 obovate, stipitate, nerveless, resinously dotted, the orifice 



21. C. ATHROSTACHYA. 



22. C. STRAMINEA. 



C. VALLICOIA. 

 C. TENELLA. 

 C. CANESCENS. 



C. DEWEYANA. 



27. C. STERILIS. 



C. ECHINATA. 

 C. ARIDA. 



30. C. SCOPARIA. 



31. 



C. LAGOPODIOIDES. 

 C. CRISTATA. 



33. C. ADUSTA. 



C. BUXBAUMII. 

 C. BIFIDA. 

 C. ATRATA. 



37. C. HETERONEURA. 



38. C. AUREA. 



C. KELLOGGII. 



C. VULGARIS. 

 C. DECIDUA. 



41. 



42. C. NUDATA. 



