North American Cyperacece. 251 
the keel. Stamens always 3, often remaining attached to the rachis after 
the fall of the scale. Style deeply 2-cleft. Nut dark-brown, exactly 
lenticular, finely striate longitudinally, with distinct transverse wrinkles. 
Hab. Low boggy places, particularly near salt water. 
Massachusetts ! to Florida ! and west to Kentucky ! Not com- 
mon. August — September. 
Obs. Our plant di.Fers in no essential character from the 
European C. Jlavescens. 
C. yoceformis of Pur.^h appears to be nothing but C. jlavescens 
in an immature and imperfect state. His specimens in Lam- 
bert's Herbarium are scarcely sufficient to dtter.r.ine the spe- 
cies with c rtanty. 
The synonym of ElUott may possibly belong to the n3xt spe- 
cies. 
2. Cyperus diandrus, Torrey. 
Umbel of 2 — 5 short rays ; spikelets lanceolate-oblong, 
much compressed, acute, many-flowered (14 — 24), alternate 
and subfasciculate on the common raolis; flowers dianc'rous ; 
scales rather obtuse, one-nerved, membranaceous ; nut oblong- 
obovate, somewhat scabrous, dull ; style much exserted ; culm 
obtusely triangular. 
C. diandrus, Tort.! cat. pi. N. York, p. 90 ; 8f fl. 1. p. 61, 
Sckult. mant. 2. p. 103 ; Spreng. ! syst. 1. p. 217 ; Beck! hot. p. 421 ; 
Darlington! fl. CeU. ed. 2. p. 15; Gray! Gram, and Cyp. part 1. 
no. 70. 
Perennial. Culm slender, 8 — 10 inches high, often bearing leaves 
half its length, frequently reclining, or decumbent, and generally solitary. 
Leaves few, bright green. Involucre of three very unequal leaves, two 
of which are 6 — 7 inches long. Umbel of few rays, which are sometimes 
so short that the spikelets are nearly sessile ; rays when elongated, very 
unequal, each bearing towards its extremity 6 — 12 sessile spikelets. 
Spikelets spreading or reflexed, much compressed, so as to appear thin 
and flat. Scales ovate, with a broad light-brown margin and a green 
keel. Stamens sometimes three in the upper florets. Style 2-cleft 
nearly to the base, the divisions 3 — 4 times the length of the nut, and 
much exserted, so as to give the spikelets a woolly appearance. Nut 
gray or light-brown, mucronate, never shining. 
