256 North American Cyperacea. 
in length, and somewhat erect. Spikelets acute, 6 — 8 lines long and one 
line broad, of a pale-yellowish colour ; the lowest ones on the common 
rachis a little compound. Partial rachis flexuous, the narrow winged 
margin formed of the confluent and persistent inner scales. Nut as in 
the preceding species. 
Hab. Near Mobile, Alabama, Dr. H. Gates! 
Obs. This species resembles C. microdontus in the spikelets 
and nut, but is otherwise very distinct. I have only received 
it from the above-named locality. 
§2. Style 3-cle/t; nut triangular ; interior scales mem- 
branaceous and adnate to the rachis, not separating in 
the inature sjpikelet, sometimes almost wanting. — Cyperus. 
a. Culm suhtercte, nodose. 
8. Cyperus articulatus, Linn, 
Umbel compound, loose ; spikelets long, linear, alternate, 
approximate; culm with leafless sheaths towards the base. 
C. articulatus, Willd. sp. 1. p. 270 ; Michx. .' fl.l. p. 27 ; Pursh, fl. 1. 
p. 50 ; Muhl.! gram. p. 18 ; Vahl, enum. 2. p. 301 ; Kunth, syn. 1. p. 137 ; 
Ram. 4" Schult. syst. 2. p. 163; N. ah Esenb. Cyp. Ind. in Wight's con- 
trih. p. 80. 
Rhizoma creeping, clothed with large lanceolate scales. Culm 2 — 6 
feet high, the middle part about as thick as a goose -quill, filled with dry 
pith, which is condensed at intervals of about an inch, producing false 
nodes, very conspicuous in the dried plant. Sheaths 2 — 3, clothing 
the lower part of the culm, and terminating in large, acute, erect 
scales, rather than leaves. Umbel of five or more primary rays, 2 — 4 
inches in length ; the rays simple or compound, each division bearing 
about 10 spikelets. Involucre yery short, 2 — 3-leaved. Spikelets an inch 
long, 15 — 20-flowered, convex on the sides. Rachis distinctly margined. 
Scales ovate-lanceolate, rather obtuse, membranaceous on the margin ; 
midrib green ; the sides whitish mixed with red. Stamens 3 ; anthers 
