North American Cyperacece. 247 
Tribe I. CYPERE^. 
Flowers perfect. Spikelets distichously imbricated 
(rarely in a spike imbricated on all sides), mostly naked, one 
or many-flowered. Perigynium none, or setaceous, or cup- 
shaped. Interior scales growing to the rachis of the spike- 
let, sometimes becoming free, or altogether wanting. Nut 
compressed or triangular, rarely rostrate or crowned with the 
persistent base of the style. 
A. With a Perigynium. 
1. DULICHIUM, Richard. 
Spikelets compressed, distichously imbricated, many- 
flowered. Bristles of the perigynium 6 — 9, rigid, retrorsely 
hispid. Stamens 3. Style very long, bifid at the sum- 
mit. Nut compressed, linear-oblong, acuminated by the 
long persistent style. — Culm terete^ leafy; leaves short and 
spreading; spikes axillary, compound, with the spikelets dis- 
tichously arranged on a common rachis. — Richard in Pers. 
syn. 1. p. 65; Ntitt. gen. 1. p. 35; Lestib. ess. fam. Cyp. p. 
37. no. 40 ; N. ah Esenb. in Linnaa, 9. p. 283. Schoeni sp. 
Vahl, &c. Cyperi sp. Linn. 
DULICHIUM SPATHACEUM, PerSOOU. 
Pers. syn. I. c. ; Pursh, jl. 1. p. 53 ; Elliott, sic. 1. p. 73. t. 
2. /. 3 ; Torr.I fl.l.ip. 58; Darlingt.! fl. Cest. p. 9. ed. 2. 
p. 17; Beck! bat. N. Sf M. St. p. 422 ; Gray! N. Amer. 
Gram. ^ Cyp. part 2. no. 131 ; Spreng. syst. 1. p. 194. 
SchcEDus spatbaceus, Linn. sp. ed. 2. p. 63. 
S. angustifolius, Vahl, enum. 2. p. 225 ; Rotm. <f Schult. syst. 2. 
p. 71. 
Scirpus spatbaceus, Michx.! fl. 1. p. 32. 
Cyperus spatbaceus, Linn. syst. p. 84 ; Willd. sp. 1, p. 289 ; Muhl.! 
gram. p. 26; Big. fl. Bost. ed- 2. p. 19. 
Ctp. racemis simplicibus lateralibus, &c. Gron. Virg. ed. 1. p. 131. 
Vol. III. 32 
