27S NoHh American CypcraeccB. 
scarious on the margin, yellowish on the sides; the keel green. Stamens 
3. Style deeply three-parted. Nut nearly as long as the scale, light 
brown. 
Hab. Lake of the Isles, North-West Territory, Dr. 
Houghton ! 
Obs. Resembles the spreading species in the disposition 
and structure of the spikelets, its large nut, and deeply 3-parted 
style ; but the umbel is nearly sessile, the glumes much broader^ 
and scarcely mucronate. 
tttt Spilcelcts siihtcretc or angular, 2 — 4:-jloivcrc(l, forming 
dense ovate or globose heads at the summit of the rays ; the 
two lowest scales commonly sterile. 
32. Cyperus ovularis. 
Culm acutely triangular ; umbel of 1 — 6 rays ; involucre 
3- — 4-leaved ; heads globose, compact ; spikelets 2 — 4-flower- 
ed, (only two of the florets fertile) radiated ; rachis winged ; 
scales ovate, rather obtuse, the two lowest short and empty ; 
hut obovate, triangular. 
Mariscus ovularis, Vahl, enum. 2. p. 374; Pursh, Ji. 1. p. 58; Torr.! 
1. p. 58(excl. syn. Ell.); Beck! Bot. p. 429; Gray.'Gi-ain. Sf Cyp. 
part 1. no. 76; Darlingt.! fl. Cest. ed. 2. p. 16; Ram. Sf Schult. syst. 
1. p. 244. 
Kyllingia ovularis, Michx. ! fl. 1. p. 29; Pers. syn. 1. p. 57. 
Scirpus echinatus, Linn.fl. Zeyl. 38?; Muhl.! gram. p. 40. 
Ctperus floribus capitatus, &c. Gron. fl. Virg. 12. 
GaAMEN Cyperoides Americanum, &c. Pluk. aim. 179. to 91. f. 4. 
Wiizoma short, tuberous. Culm 1 — 2 feet high, slender, smooth on the 
angles. Leaves all radical, shorter than the culm, 2 — 3 lines wide. 
Rays of the umbel simple, 1 — 2 inches long, sometimes contracted, so 
that the heads appear to be almost sessile. Ochrea obtuse. Involucre 
many times longer than the umbel. Heads about half an inch in dia- 
meter, exactly globose, composed of 50 — 100 spikelets whicli radiate in 
every direction from the common rachis. Spikelets commonly about 3- 
flowered, short and thick, rather quadrangular than terete. Sealery ap- 
