80 Cyperaceae 
Il. Perigynia green; lower scales of the spike foliaceous, much exceeding the 
perigynia. 
J. Pistillate scales cuspidate. C. E. 
(3 geyeri Boott 
JJ. Pistillate scales long-acuminate. U. 
C. multicaulis Bail. 
HH. Perigynia shorter than the scales of the spike. 
K. Perigynia beakless, obtuse or emarginate at tip. W. C. 
C. leptalea Wahl. 
KK. Perigynia beaked, beak entire. 
L. Perigynium-beak oblique at tp. 
M. Stems 5—15 cm. high; spike 12 mm. or less long; perigynia brown 
to purple. E. C. obtusata Lili. 
MM. Stems 12—45 cm. high; spike 12—24 mm. long; perigynia straw- 
colored. C. OC. breweri Boott 
LL. Perigynium-beak not oblique at tip. E. 
C. filifolia miser Bail. 
GROUP 2 
A.  Pistillate spikes 1850 mm. long; scales acute or acuminate or cuspidate; peri- 
gynia green or rusty-brown. 
B. Perigynia hairy on the angles only. W.C. E. (C. frigida.) 
C. ablata Bail. 
BB. Perigynia hairy thruout except on the beak. 
C. Leaves rolled up, about 2 mm: wide; stem 6—9 dm. high, smooth. W. C. E. 
C. filiformis L- 
CC. Leaves flat, wider. 
D. Stem rough above, 3—8 dm. high. W. E. 
C. lanuginosa Michx. 
DD. Stem smooth, 2—4 dm. high. C. E. 
C. oregonensis Oln. 
AA.  Pistillate spikes 4—18 mm. long (occasionally longer in C. concinnoides but in 
that the scales are obtuse or rounded); scales various at apex; perigynia various in 
color. 
E. Stem equaling or exceeding the leaves. 
F. Stem leafless between the basal tuft and the bracts of the inflorescence. 
G. Pistillate scales brown at least in the middle, sometimes scarious-margined. 
H. Spikes all sessile, even the staminate so; perigynia white or light-colored. 
We CGa C. verpertina How. 
HH. Some of the spikes stalked, the staminate at least so; perigynia brown 
at base. C, C. inops Bail. 
GG.  Pistillate scales green or whitish. (See EE.) 
FF. Stem with some leaves or leaf-like bracts between the basal tuft and the 
bracts of the inflorescence. 
I. Perigynia loosely pubescent, wider and longer than the ‘scales; staminate 
spike nearly sessile; pistillate spikes few-flowered. E. 
C. concinnoides Mack. 
II. Perigynia appressed pubescent, narrower and shorter than the scales; stam- 
inate spike evidently stalked; pistillate spikes many-flowered. E. 
C. richardsonii R. Br. 
EE. Stem exceeded by the leaves. 

