202 CYPERACEAE 
XVI. PSEUDO-CYPEREAE 
Perigynium  obtusely triangular, eniin e ee 
stoloniferous : ligule much lence aan e. . 121. C. comosa. 
Perigynium suborbicular in. cross-section, iors or less 
inflated : oe long stoloniferous: ligule wider 
than lon 199. C. Schweinitzii 
XXXVII. SQUARROSAE 
Scales exceeding perigynia: terminal spike small, nor- 
mally staminate. 123. C. Frankii. 
Seales much shorter than perigynia: terminal spike 
gynaecandrous. 
Achene linear-oval with flattish sides: style strongly 
sinuous or abruptly bent below: spikes oval, the 
perigynia with D. T AURE beaks : pistillate 
scales acuminate or 124. C. squarrosa. 
Achene obovoid with a sides: style straight 
below: spikes oblong-cylindric, the perigynia 
mostly with beaks appressed-ascending: pistil- 
late scales obtus ish. 125. C. typhina. 
XXXVIII. LUPULINA 
Pistillate spikes globose or subglobose: style bci 
st 
sto : 
Perigynium rounded at base, membran aceous, shin- 
: - 2.5- 
mm. wide, their d short-prolonged upward 
at m. ‘beyond base of blade: pistillate spikes 
1-15-flowered. 126. C. intumescens. 
Perigynium cunesta at base, firm, dull, often his- 
Du lJeaf-blades 4.5-14 (averaging rte 
mm. wide, their sheaths not prolonged upward at 
mouth beyond base of blade: pistillate spikes 
6-30-flowered. 127. C. Asa-Grayi. 
Pistillate spikes oblong or cylindric: RAM abruptly 
bent: stolons long, slender, horizonta 
Perigynium ascending, the beak less Tet twice the 
length of the body. 
€ulms arising singly from elongate rootstocks: 
` leaf-blades 2-5 2n wide: pistillate scales 
acute or acumin 128. C. louisianica. 
Culms eespitose : ha blade s 4-12 mm. wide: pis- . 
tillate scales acuminate or aristate. 129. C. lupulina. 
Berega spreading at right a the DEN . 
two to three times the length of the body 130. C. gigantea. 
I. MUHLENBERGIANAE Tuckerm. Densely cespitose or a few species with 
the rootstock e d tough, and dark-colored. Culm not flattened. Opaque 
part of sheaths neither transversely rugulose nor red-dotted. Spikes usually 
10 or less, caben e or pistillate, but not Spyies oro) rarely at all com- 
pound.  Braets from little to strongly 
veloped. Perigynium plano-convex, green or 
chestnut-tinged or light-brownish in age, 
from appressed to reflexed, often strongly 
gy at base, SS Or ringl 
spon e, rve 
nerved, narrowly sharp-margined, conspicu- 
ously be the beak sharply bidentate 
aked, 
ehene lenticular. Style-base more or less 
thickened. Stigmas 
1. C. retroflexa Muhl. Culm slender, stiffish, 
2-5 dm. tall: leaf-blades 1-2.5 mm. wide: 
-flo 
u 
gated, the lower 1-3 separated: perigynium 
3 mm. lon i 
