>ISZ Order 1 56.— OYPER AOKjE. ' 



5 Teieb i. OAEICEjE. Glumes imbricated or alternate. Setffl 0. Perianth 

 (perlgyniiim) of united scales, sac-lilte, enclosing the acbooium. Style 2 or 8- 

 oleft. Flowers diclinous Caeei, IT 



1. DULICH^IUM, Rich. (Gr. dvw two, Xetxov, 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 witfci 6 to 9 

 barbed seta3. — 21 St. leafy. Spikes sessile, alternately arranged in 2- 

 rowcd, axillary racemes. 



D. spath^oeum Pers. Marshes, borders of streams, U. S. and Can. St. round, 

 leafy, and somewhat 3-sided above, thick, sheathed below. Lvs. alternate, pointr 

 ing 3 ways, 2 to <t' by 3''- Sheatlis tubular, shorter than the internodes. Clus- 

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

 linear-lanceolate, alternate spikes in 2 rows. Spikes 5 to T-fiowered, nearly on 

 inch in length. Glumes linear-lanceolate. Aug. 



2. CYPE'RUS, L. Galingale. 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 setas ; stamens 3, rarely fewer ; style 3-fid (rarely 2-fid), decid- 

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

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



§ Ptceeus. style 2-cleft. Achenium lens-shaped. Spiltes flat, 10 to 30-flo\vcred.— 



—Stamens 2 (partly 8 in No. 1) Nos. 1—8 



— Stamens always 8 Nos. 4. .'> 



§ CYPBuas. Style 8-cleft. Achenium 3-nngled. Spikes flattened or teretisb, 5 to 40- 

 flowered, the one lowest glume empty. (*) 



* Culm with manyjomts, teretish, and with leafless sheaths at base Nf B 



* 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 Spikes racemously arranged along the rachis. Stamens 8. (c) 



c Spikes 10 to 20-flowered, the clusters 2-rowed Nob. S. P 



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 fi.attened, linear or lanceolate Nos. 18— l.*! 



b Spikes capitate on the summit of the rachis. (e) 



1 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-flowerer] No. 19 



—Spikes flattibh, 6 to 10-flowered .'Nos. 20, 21 



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



f Umbel compound. Spikes G to 80-fluwered Nos. 23— 2ri 



J MAE180T78. Style 8-cleft. Achenium 8-angled. Spikes teretish, 1 to 4-flowerod, in 



dfnse lieads, the 2 lowest glumes empty Nos. 26, 27 



1 C. di^odrus Torr. Culms slender, reclining, 4 to 10' high ; ttmM contracted, 

 of 2 to 5 short, unequal rays; spilces flat, ovate or oblong, 12 to 24-flowered, obiu- 

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

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

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



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



/3. CASTANEUS. Scales of a dark chestnut color, shining, coriaceous, closely iK>- 



bricated ; styles scarcely exserted. 

 J. PAUOir.LOKtJS. Spikes very short, 5 to 9-flowered ; glumes chestnut brown, 



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



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

 short, loese; spihes (2 to 6'' long) linear-lanceolate, flattened, very acv,te, 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. L^ s. 

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

 6 «o 12" long, in loose, m'egular umbels. Aug. 



