732 Ordbe 155.— CyPEEACEiS. 



S Tbihe 4. CAEICE^. Glumes imbrlonted or alternate. Setae 0. Perianth 

 (perigynlum) of united scales, sao-Iike, enclosing the aohenium. Style 2 or S- 

 cleft. Flowers diclinous Caebx. 17 



1. DULICH'IUM, Rich. (Gr. 6v(o two, ?ieixov, scale; the glumes 

 are in two rows.) Spikes linear-lanceolate, subcompressed ; glumes 

 sheathing, closely imbricated in 2 rows; style long, bifid, the persistent 

 base crowning the compressed achenium ; ovary invested with 6 to 9 

 barbed setse. — U St. leafy. Spikes sessile, alternately arranged in 2- 

 rowed, axillary racemes. 



D. apathaoevim Pers. Marshes, borders of streams, U. S. and Can. St. round, 

 leafy, and somewhat 3-sided above, thick, sbe.athed below. Lvs. alternate, polnt- 



' ing 3 ways, 2 to i' by 3''. Sheaths tubular, shorter than the Interaodes. Olus- 

 ters axillary from within the sheaths, and terminal, each consisting of 8 to 10 

 linear-lanceolate, alternate spikes in 2 rows. Spikes 5 to 7-flowered, nearly an 

 inch in length. Glumes linear-lanceolate. Aug. 



2. CYPE'RUS, L. Galingalb. Sedge. (Gr. Kvneipog, the ancient 

 name.) Spikes compressed, distinct, many-flowered ; glumes imbri- 

 cated in 2 opposite rows, nearly all with a flower enclosed ; flowers 

 without set£B ; stamens 3, rarely fewer ; style 3-fid (rarely 2-fid), decid- 

 uous. — Mostly '21 . St. simple, leafy at base, mostly triangular, bearing 

 an involucrate, simple or compound head or umbel at top. 



§ Pycekus. stylo 2-oleft. Aolienium lens-shnped. Spikes flat, 10 to 80-flowerefl.— 



— Stivmens 2 (partly 3 in No. 1) Nos. 1—8 



—Stamens always 8 , Nos. 4, 5 



§ CjPBBns. Style 8-cTeft. Achenium 8-anglcd. Spikes flattened or teretish, to 40- 

 flowered, the one lowest glume empty. (*) 



* Culm with many jomts, teretish, and with leafless sheaths at base No. 6 



* Culm jointless, triquetrous, and with leaves below, (a) 



a Pair of scales within each glume free, persistent. Heads dense No. 7 



a Pair of scales adnate to the rachis, or wanting, (b) 



b Spifees racemously arranged along the rachis. Stamens 3. (c) 



c Spikes 10 to 20-flowered, the clusters 3-rowed... Nos. 8,9 



c Spikes 5 to 7-flowered, the clusters 2-rowed No. 10 



C Spikes 5 to 10-flowered, clusters many-rowed, (d) 



d Spikes terete or tetragonal Nos. 11, 12 



d Spikes flattened, linear or lanceolate Nos. 18—15 



b Spikes capitate on the summit of the rachis, (e)' 



e Glumes with recurved points. Stamen 1 only Nos. 16, 17 



e Glumes with erect points. Stamen 1 only No. 18 



e Glumes with erect points. Stamens 8. (f ) 



f Umbel simple. — Spikes terete, few -flowered No. 19 



—Spikes fl.atti.sh, 6 to 10-flowcred Nos. 20, 21 



—Spikes flat, 12 to 40-flowered No. 22 



f Umbel compound. Spikes 6 to 30-flowered Nos. 28 — 25 



§ Mariscus. Style 3-cleft. Achenium 3-angled. Spikes teretish, 1 to 4-flowered, in 



dense heads, the 2 lowest glumes empty Nos. 26, 27 



1 C diandrus Torr. Culms slender, reclining, 4 to 10' high; vmhel contracted, 

 of 2 to 5 short, unequal rays; spi/ces fleet, ovate or oUong,12 to 24-flowered, dbtvr 

 sish, fascicled at the top of the rachis ; glumes obtusish, 1- veined, membranous; 

 green on the keel, the sides rust-colored in various shades ; stam. mostly 2 ; sty. 

 2-cleft, exserted ; ach. obovate, dull. — Mai;shy grounds, N. E. to 'W. States, com- 

 mon. A handsome Sedge. Scales 5 to 8" long, near 2'' wide. Aug. 



^. oASTANEus. Scales of a dark chestnut color, shining, coriaceous, closely im- 

 bricated ; styles scarcely exserted. 



y. PAUOiFLORUS. Spikes very short, 5 to 9-flowered; glumes chestnut brown, 

 with yellowish margins; lvs. linear-setaceous. — N. Ohio. 



2 C. Nfittdllii Torr. Culms triquetrous, tufted, 4 to 12' high; rays few and 

 short, loose; spikes (2 to 6'' long) liTiear-lanceolate, flattened, very acute, 10 to 20- 

 flowered ; scales acute, loosely imbricated, yellowish-brown ; stam. 2 ; ach. oblong- 

 obovate, obtuse, with a half 2-cleft style. — ^Brackish meadows, Mass. to La. Lvs. 

 mostly shorter than the culms. Invol. of 4 leaves, 2 of them very long. Spikes 

 6 to 12" long, in loose, irregular umbels. Aug. 



