Eleocharis. CLX. CYPERACE^. 5G9 



Tribe 3. SCIRPEJ3.— Flowers ^ . Glumes of the spikelet imbricated all 



around. Pcrigynium none, or setaceous. 



G. ELEOCHArIS. R. Br. 



frr. e\oi, a marsh, )(^aipo}y to rejoice ; iihinU delighting in marshy grounds. 



Spikes terete ; bristles of the pcrigynium mostly G (3 — 12), rigid, 

 persistent ; styles 2 — 3-c'lcft, articulated to the ovary ; achenium 

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

 style. — S(e//i simple, leajicss. Spike solitary, terminal. 



^ Spikes ci/lindrical, length more than three times the diameter. 



1. E. EauisKTiiiDK.s. Torr. (Scirpus. EUidtt.) Horse-tail Rush. 



St. about 2r high, papillose, terete, 2 — 3" diam., with about 20 joints, pro- 

 duced by internal, transverse partitions; .s/ua/k radical, obtuse, membranous; 

 spi/i-c oblong-cylindrical, about 1' in length, acute and slightly contracted at 

 Dase ; i;/«w^.s- roundish-ovate, cartilaginous, obtuse; bristles 6, as long as the 

 achenium; ^lif. 3-clert ; ach. brown, shining. — Bogs, Cumberland, R. I., Olney ! 

 Del. to Ga. It strikingly resembles Equi.setum hyemale. 



2. E. ai'ADRANGULATA. R. Br. (Scirpus. Mirhx.) 



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

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

 glumes roundish-ovate, obtuse, coriaceous; bristles 6; ach. obovate, of a dull 

 white. — Penn., Md., Dr. Rubbins, to Ga. and La. In swamps and inundated 

 banks. 



3. E. Robbinsii. Oakes. Robblns' Chib Ritsh. 



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 G, twice longer than the achenium; ach. I" long, pale broAvn ; 

 tubercle clo.sely 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 ; spikelets .smooth and shining, lance-oblong, 

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

 times empty. — 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, rugo.se, punctate, surrounded with 3 or 4 scabrous bristles, and 

 crowned with a tubercle. July. 



5. E. OBTtsA. Schultes. (Scirpus ©"btusus. Willd. Scirpus capitatus. Walt.) 

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

 ly globose ; ghimcs round, dark broAvn, with whitish margins; ach. obovate, 

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

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



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



St. columnar, striate, 12' high, leafless, sheathed at base ; spikelet ovate- 

 lanceolate ; ghrmcs 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. 

 * * Stems compressed or angular. 



7. E. OLIVACKA. Torr. 



Sts. caespitose, 2 — 4' high, slender, compressed, sulcate, soft ; spike ovate, 

 acutish 2 — 3" long, 20 — 30-flowered ; glumes ovate, obtu.se, reddish-brown, with 

 scarious edges and a green midvcin, the loM'est largest ; bristles G ; sty. 2-cIeft ; 

 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. Schultcs. (Scirpus. Muhl.) Turf Club Rush. 



St. caespitose, .setaceous, diffuse, compressed, furrowed, hard and wiry. 



