. 
Cyperaceae 79 
Subgenus EUCAREX—Pistillate spikes distinct or rarely again bunched into 
heads or panicles, mostly peduncled. Staminate spikes | or more, terminal, linear or 
club-shaped, often pistillate at base or apex, or rarely with some pistillate flowers” in- 
termixed. Stigmas 2—3. Akenes lens-shaped or 3- angled. 
A. Stigmas 3; akenes 3-angled. 
B. Spike only 1, terminal. Group | (p. 79) 
BB. Spikes more than 1. 
- CC.  Perigynia hairy. Group 2 (p. 80) 
CC. Perigynia smooth. 
D. Beak or opening of the perigynium plainly 2-toothed. 
E. Scales of the spike rough-awned. Group 3 (p. 81) 
EE. Scales of the spike awnless or smooth-awned. Group 4 (p. 81) 
DD. Beak or opening of the perigynium entire, or slightly and bluntly notched, 
or split down | side. GrouP 5 (p. 82) 
AA.  Stigmas 2; akenes lens-shaped. 
F. Scales of the pistillate spikes green or yellowish, sometimes somewhat purple- 
margined. GrouP 6 (p. 83) 
FF. Scales of the pistillate spikes brown or purple or black. 
G. Scales of the pistillate spikes with mid-vein excurrent as an awn or mucro, 
or the scales very acute to acuminate. Group 7 (p. 83) 
GG. Scales of the pistillate spikes without excurrent mid-vein, acute to rounded. 
H. At least the lower pistillate spikes drooping; perigynia equaling or shorter 
than the scales (longer in C. mertensii.) Group 8 (p. 84) 
HH.  Pistillate spikes erect to merely spreading. 
I. Perigynia equaling or exceeding the scales. GrouP 9 (p. 84) 
II. Perigynia shorter than the scales. Group 10 (p. 85) 
GROUP 4 
A. Perigynia scabrous or hairy. 
B. Scales of the pistillate spike with tip ciliate-margined. 
C. Perigynia about 2 mm. long, oval to obovate; scales dark-purple. W. C. E. 
C. scirpoidea Michx. 
CC. Perigynia about 4 mm. long, lanceolate; scales black, C. E. 
C. stenochlaena Mack. 
BB. Scales of the pistillate spike not ciliate-margined. 
D. Spike bractless; perigynia broadly triangular-obovoid. E. 
C. filifolia Nutt. 
DD. Spike bracted; perigynia lanceolate. C. 
C. scabriuscula Mack. 
AA. Perigynia smooth. 
E.  Perigynia lanceolate or spindle-shaped. 
F. Perigynia Z—3 times as long as the scales, greenish. W. 
C. pauciflora Lft. 
FF. Perigynia (ae times as long as the scales, brown. 
eS: Tae the shining; staminate flowers occupying | /3 or less of the spike. 
C. pyrenaics, Wahl. 
GG. Be erciiis dull; staminate flowers occupying about 1/4 of the spike. C. E. 
C. nigricans Mey. 
EE. Perigynia ovate or elliptic or obovate. 
H. Perigynia exceeding the scales of the spike. . 
I. Perigynia straw-colored; lower scales of the spike not foliaceous, little if at 
all exceeding the perigynia. C. C. paddoensis Suks. 

