192 CYPERACEAE 
lar, or plano-convex, completely surrounded by the perigynium or rarely rup- 
turing it in ripening.  Racheola occasionally developed.—Comprises 1,000 
species, widely distributed, but most abundant in temperate regions.—SEDGES. 
Achene lenticular and EE two: lateral spikes sessile: terminal spike DET pis- 
tillate, or if (rarely) staminate the lateral spikes short, or heads dioecio 
Spikes strictly EE (4.€., with the stáminate flowers uppermost). 
pikes few (ten or less): Der mum green 
u -ripe. 
SDE aoe : perigynium yellowish or 
nis 
as a abruptly contracted into the 
eak. 
Perigynium yellowish: opaque part of leaf- 
sheath usually transversely rugulose. 
rig 
Spikes, some or all of them, gynaecandrous (i.e., 
staminate at base) : some often entirely pis- 
tillate or some occasionally entirely staminate 
or staminate at both ends. 
Perigynium appres 
Seren um AAT or ascending at ma- 
Perigynium narrowly to broadly wing-mar- 
Achene triangular and styles three, or lenticular and 
ytes o: if lenticular, oe a spikes 
a ly peduncled, terminal spike 
staminate and lateral spikes "dun 
Achene rounded at apex, x rongly Cols a at 
base: lower scales bract- 
Achene o DEC ot strongly eee 
a S 
Spike one: perigynium rounded Hg ce beak- 
less, glabrous 
Sp pu one or more, when one not as described 
ve. 
Perigynium triangular, or circular in cross- 
section, ~closely- enveloping the achene, 
2-ribbed, stipitate, tapering at the base, 
pubescent or puberulent, at least at the 
o of d beak: bracts sheathless or 
early s 
BO cone triangular: foliage 
not pubes 
E pee triangular: foliage 
ten pubescent. 
of 
Perigynium glabrous or minutely hispidu- 
. lous or pubescent: if ST some or 
of the other roe differing 
from those given a 
Lowest Dract strongly “gree n-sheathing : 
beak of perigynium, if present, rarely 
pne Du but a a the apex hyaline 
an 
Spike Hors on ne. 
Spikes two or mo 
Bracts with obsolete or rudimentary 
Leaf-blades flat: perigynium pu- 
berulent to pubescent 
Leaf-bl a filiform:  perigynium 
g 
Bracts with well- developed blade 
s. 
U s o Short-oblong to 7 
r 
nyc triangular: terminal 
Spike staminate. 
X 
RR tee eo 
I. MUHLENBERGIANAE. 
II. MULTIFLORAE. 
III. PANICULATAE. 
IV. STENORHYNCHAE, 
V. CANESCENTES. 
VI. DEWEYANAE, 
VII. STELLULATAE. 
VIII. OvALES. 
IX. PHYLLOSTACHYAE. 
X. POLYTRICHOIDEAE. 
XL Mon TANAE. 
er 
XII. TRIQUETRAE. 
XIII. PICTAE. 
XIV. DIGITATAE. 
XV. ALBAE. 
