EuBoonaris. CLX. CYPERACER. 569 
Tre 3. SCERPEZ.—F lowers §. -Glumes of the spikelet imbricated all 
around. Perigynium none, or setaceous. 
6 ELEOCHARIS. R.Br. 
Gr. éX0s, a marsh, Xatow, to rejoice; plants delighting in marshy grounds. , 
Spikes terete; bristles of the perigynium mostly 6 (3—12), rigid, 
persistent; styles 2—3-cleft, articulated to the ovary; achenium 
erowned with a tubercle which is the persistent, bulbous base of the 
style.—Stem simple, leafless. Spike solitary, terminal. 
§ Spikes cylindrical, length more than three times the diameter. 
1. E. equiseTéipes. Torr. (Scirpus. Ellictt.) Horse-tail Rush. 
St. about 2f high, papillose, terete, 2—3” diam., with about 20 joints, pro- 
duced ‘by internal, ‘transverse partitions; sheath radical, obtuse, membranous; 
spike oblong-cylindrical, about 1’ in length, acute and slightly contracted at 
pase ; glumes roundish-ovate, cartilaginous, obtuse; bristles 6, as long as the 
achenium ; sty. 3-cleft; ach. brown, shining.—Bogs, Cumberland, R. I., Olney! 
Del. toGa. It strikingly resembles Equisetum hyemale. 
2. E. QuaDRANGULATA. R. Br. (Scirpus. Michz.) 
St. 2—4f high, acutely and unequally quadrangular, the broadest side 
convex, the others concave ; sheaths radical, purplish ; spike 1’ or more in length; 
glumes roundish-ovate, obtuse, coriaceous ; bristles 6; ach. obovate, of a dull 
white—Penn., Md., Dr. Robbins, to Ga. and La. In swamps and inundated 
banks. 
3. E, Rossinsiu. Oakes. Robbins’ Club Rush. 
Sts. clustered, 9—25’ high, rigid, sharply triangular, pale green, several 
of them fruitless; sheath truncate; spike 3—12” long, scarcely thicker than the 
stem, placed 2—5” below its apex! glwmes 3—9, linear-lanceolate, acute, finally 
‘brownish ; bristles 6, twice longer than the achenium; ach. 1’’long, pale brown 
tubercle closely sessile-—Ponds and ditches, N. H. and Mass., Rickard! Very 
distinct. In water a part of the stems are floating and as fine as hairs. July. 
§ § Spike ovate, length less than three times the diameter. * Stems terete. 
4. E. patustris. R. Br. (Scirpus. Linn.) Marsh Club Rush. 
St. leafless, round, inflated; spikelets smooth and shining, lance-oblong, 
acute, often oblique, terminal; glwmes subacute, the lower ones larger, some- 
‘times empty.—Low grounds, U.8. and Brit. Am. Root creeping. Stems nu- 
merous, 1—24f high, each with an obtuse sheath at the base. Achenium round- 
ish-obovoid, rugose, punctate, surrounded with 3 or 4 scabrous bristles, and 
‘crowned with a tubercle. July. 
5. E. oprisa. Schultes. (Scirpus obtusus. Willd. Scirpus capitatus. Walt.) 
St. sulcate, subterete, 6—15’ high; spikelet ovoid, very obtuse, often near- 
ly globose ; glumes round, dark brown, with whitish margins; ach. obovate, 
compressed, smooth, brown, invested with 6 sete as long as the glumes.—Shal- 
low waters, Can. and U.8., common. July. 
6. E. TupercuLosa. R. Br, (Scirpus. Michz.) 
St. columnar, striate, 12’ high, leafless, sheathed at base; spikelet ovate- 
lanceolate; glumes very obtuse, loose; ach. somewhat triquetrous, smaller than 
the sagittate tubercle with which it is crowned ; bristles 6, as long as the tuber- 
cle.—Sandy swamps, N. Eng.! to Flor. Remarkable for its large tubercle. Jl. 
* * Slems compressed or angular. 
7. E. ontvacea. Torr. 
Sts. ceespitose, 2—4’ high, slender, compressed, sulcate, soft; spike ovate, 
acutish 2—3” long, 20—30-flowered ; glumzs ovate, obtuse, reddish-brown, with 
scarious edges and a green midvein, the lowest largest; bristles 6; sty. 2-cleft; 
ach. broadly obovate, smooth, of a dull, blackish-olive color when ripe.—Sands, 
generally partly submersed, Providence, R. I., Olney! Mass. to N. J. 
8. E. InTeRMEDIA. Schultes. (Scirpus. Muhl.) Turf Club Rush. 
St. czespitose, setaccous, diffuse, compressed, furrowed, hard and wiry, 
