Eleocharis. CLX. CYPERACE^. 569 



Tribe 3. SCIRPE^E.— Flowers $ . Glumes of the spikelet imbricated all 

 around. Pengynium none, or setaceous. 



6. ELEOCHARIS. R. Br. 



G-r. cXof, a marsh, ;(;a(j3w, 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 

 crowned with a tubercle which is the persistent, bulbous base of the 

 style. — Stem simple^ lea/less. Spike solitary^ terminal. 



^ Spikes cylindrical.^ length more than three times the diameter. 



1. E. EauisEToiDEs. Torr. (Scirpus. Elliott.) Harse-tail Rush. 



St. about 2t'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 

 Dase ; glumes roundish-ovate, cartilaginous, obtuse ; bristles 6, as long as the 

 achenium ; sty. 3-cleft ; ach. brown, shining. — Bogs, Cumberland, R. I., Olney I 

 Del. to Ga. It strikingly resembles Equisetum hyemale. 



2. E. auADRANGULATA. R. Br. (Scirpus. Michx.) 



St. 2— 4f high, acutely and unequally quadrangular, the broadest side 

 convex, the others concave ; sheaths radical, purplish ; spike V or more in length ; 

 glum£S 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. RoBBiNsii. 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 ! glumes 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. PALUsTRis. R. Br. (Scirpus. Linn.) Marsh Club Rush. 



St. leafless, round, inflated ; spikelels smooth and shining, lance-oblong, 

 acute, often oblique, terminal ; glumes subacute, the lower ones larger, some- 

 times emptv.— Low grounds, U. S. and Brit. Am. Root creeping. Stems nu- 

 merous, 1— 2if 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. OBTUSA. Schultes. (Scirpus ol)tusus. Willd. Scirpus capitatus. TfW/.) 

 St. sulcate, subterete, 6 — 15' high ; .^pikelet ovoid, very obtuse, often near- 

 ly globose ; glumes round, dark browii, with whitish margins; ach. obovate, 

 compressed, smooth, brown, invested with 6 setae as long as the glumes. — Shal- 

 low waters. Can. and U. S., common. July. 



6. E. TUBERCULOSA. R. Br. (Scirpus. Michx.) 



5^«. columnar, striate, 12' high, leafless, sheathed at base; spikelet ovate- 

 lanceolate ; glumes very obtuse, loose ; acJi. 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. 

 ♦ * Stems compressed or angular. 



7. E, oLivACKA. Torr. 



Sts. c.xspitose, 2 — 1' high, slender, compressed, sulcate, .soft; spike ovate, 

 acutish 2 — 3' long, 20 — 30-rtowered ; glum<:s Dvate, obtuse, reddish-brown, with 

 scarious edges and a green mid vein, the lowrst largest ; bristles G ; .''7//. 2-cleft; 

 ach. broadly obovate, siaonih, of a dull, Idai-kish-olive eolor when ripe. — Sands, 

 generally partly subnit-rsed, Pruvidfiiee, U. I., Olnry! Mass. to N. J. 



8. E, iNTKKMKDiA. Sfhullcs. (Scirpus. Muhl.) Turf Club Rus/i. 



St. ra;spiio.se, .setaceous, diffu-se, coiupres.scd, furrowed, hard and wiry. 



