Cyperaceae 85 
CC. Lowest spikes loosely-flowered at base; perigynium-beak entire or barely 
emarginate. 
D. Lower spike long-stalked. C. 
C. nudata anomala Bail. 
DD. Lower spike short-stalked. W. C. E. 
C. interrupta Boeck. 
AA.  Pistillate scales purple. 
E. Leaves 2—4 mm. wide; pistillate spikes about 2 mm. thick: scales obtuse. W. 
[Say De C. kelloggii Boott 
EE. Leaves 6—8 mm. wide; pistillate spikes 6—8 mm. thick; scales acute or 
acuminate. C. E. C. reynoldsii Dew. x 
AAA.  Pistillate scales black. 
F. Perigynia granulate, yellowish-green; pistillate spikes about 2. W. C. E. 
.C. gymnoclada Holm 
FF. Perigynia smooth, almost white; pistillate spikes about 4. E. (C. hallit.) 
C. pulchella Holm 
GROUP 10 
A.  Pistillate spikes globose to oval. 
B. ‘Terminal spikes staminate below only; pistillate scales black. C. E. 
C. alpina Sw. 
BB. Terminal spike entirely staminate; pistillate scales dark-purple.  E. 
C. bigelovii Torr. 
AA.  Pistillate spikes oblong or longer. 
C. Pistillate scales black, obtuse; perigynia green or whitish thruout. E. 
C. variabilis Bail. 
CC. Pistillate scales dark-purple, obtuse or acute; perigynia purplish above. [ee 
D. Stem scabrous; pistillate spikes 2—3 mm. thick; pistillate scales obtuse. 
C. E. (C. nudata versuta; C. nudata angustifolia. ) 
C. nudata, Boott i 
DD. Stem usually smooth; pistillate spikes 4-6 mm. thick; pistillate scales acute. 
C. E. (C. rigida hesperia.) 
C. rigida Good. 
Subgenus VIGNEA—Pistillate spikes usually more or less bunched into heads or 
even panicles. Spikes mostly uniform and sessile, bearing staminate flowers at base’ 
or apex or among the pistillate ones. Stigmas 2. Cross-section of perigynium plano- 
convex. Akene lens-shaped. 
A.  Staminate flowers borne at the top of the spikes. 
B. Spikes densely packed so the individual ones are hardly discernible, or spike only 
l. Group I] (p. 86) 
BB. Spikes more loosely packed so the individual ones are easily discernible but 
touching or nearly so. Group 12 (p. 86) 
BBB. At least the lower spikes separated by 5 mm. or more of space. 
Group 13 (p. 87) 
AA. Staminate flowers borne at the base of the spikes or scattered among the pis- 
tillate flowers. 
C. Spikes all aggregated into an uninterrupted head. Group 14 (p. 87) 
CC. At least the lowest spikes separated by 5 mm. or more of space. 
Group 15 (p. 88) 
