CYPERACEAE 
Spikelet-scales closely concealing the 
achenes: perianth-bristles very short 
or paca atid achene pyriform, about 
. long, whitish the tubercle a 
"ike crown with a minute tip. . E. Brittonii. 
with an acicular blade: 
. E. carolina. 
Achen paced: Serculate, broadly obovoid. 27. E. Curtis. 
Spikelets flattened, 2-6- flowered, Oron OTO rous, 
Achene obovoid : tubercle deltoid or depressed. . E. prolifera. 
Ac Hene ellipsoid or nearly so: tubercle abruptly 
subulate- Vpred . E. Baldwinü. 
doge Elend or S 
ap vis "plainly distinguishable from the achene. 
moo 
Tubercle d covering the top of the black 
achen 30. E. melanocarpa. 
Tubere ie low-conic, acute, contracted at the base. . E. albida. 
Achene papillose or TL ridged-reticulate. 
Achene with the 3 angles ribbed. . E. tricostata. 
Achene obtusely 3-an led. 
slender to occ filiform, not flat- 
ien ed: seales obtuse. 
Bristles 2-4, shorter than the achene: 
achene strongly papillose. 33. F. capitata. 
Bristles 6, the longer as long as the 
achene: achene desi reticulate. 34. E. arenicola. 
Scape flattened: scales acu 35. E. acuminata. 
Tubercle conic-subulate or pyramidal, andy distin- i 
guishable from the achene. 36. E. rostellata. 
E. equisetoides (Ell.) Torr. aaa up to 1 m. tall, the scapes nodose, 
leaf-sheaths often ect ie ing: spike elet cylindric, 2.5-4 em. long, 
flowere d boris s mostly o Bun 
long, owly margin b. ps E 
bristles as ree d the achene or Ern Or 
Tex., Mich., and Mass.—(W. I., Mex 
S. A.) i 
2. p cellulosa Torr. Perennial, up to 8 
dm the scapes not nodose, terete Da 
leaf- sheathe bladeless, sometimes short-tip- 
pe dd spikelet cylindric, 1.5-3 em. long, many- 
: | scales rounded, 4-5 mm. long, 
owered: 
pas -margin ned: perianth- lager smooth, 
longer than the achene: achene obovoid, about 2 mm. long, dark-brown, bond 
coarsely pitted, the tubercle oe very stout, 42-14 as long as the a che — 
Fresh marshes and lagoons near the coast, Fla. to Tex.— —(W. I.) 
3. E. quadrangulata (Michx.) R. and S. Perennial, up to 1. 2 m. tall, the 
RR not nodose: 
m. long, many-flower 
unded: S ar "bristios as long as the achene or longer: achene obovoid, 
.5 mm. long, brown, the tubercle lanceolate, poe half as foie as the achene, 
ipis at the base. [E. mutata (Fl. SE U. S.) ]—Ponds, a and 
swamps, various provinces, Fla. to Tex., Mo., Mich., Ont., and Con —(W. PR 
Mez., C. A., S. A.) 
. B. Robbinsii Oakes. Perennial, 2-7 dm. tall, the scapes 3-angled, produe- 
ing tufts of very slender scapes or leaves: leaf- sheaths not blade-bearing: 
11 
