CliASS IV. GliUMACEOUS ENDOGEXS. 



Flowers with glumes ; or floral organs enclosed in imbricated 

 bracts, and arranged in spikelets, having no proper perianth (calyx 

 or corolla). Ovary with one cell containing a solitary ovule and 

 becoming a one-seeded fruit (achenium or caryopsis). 



Order CLX. CYPERACEJE— Sedges. 



Herbs mostly perennial, coarse, grass-like, caespitose. Root fibrous or rarely tuberous. 



Stems (culms) usually solid with pith, generally without joints or nodes, and triangular. 



Lvs. with their sheaths entire. Inflorescence mostly capitate orspicate. 



Fls. perfect or monoecious, solitarj' in the axil of each bract (glume, scale). 



Per. wanting, or represented by a few hypogjnous bristles, or a cup-shaped or saccate perigynium. 



Sta. definite (1—12), mostly 3. Anthers fixed by their base, entire, 2-celled. 



Ova. generally either surrounded by bristles, or invested in the saccate perigyniuTn. Ovule erect. 



Sti/. 2 or 3, more or less united. Stigmas undivided, rarely bifid. 



Fr. an achenium. Embryo in the end of the albumen ne.xt the hilum. 



Genera 1 12, species 2000. The sedges abound in almost all countries and climes of the globe, and in all 

 localities, but are more common in the meadows, marshes and swamps of the temperate zones. About 

 25 genera and 340 species are known in North America. 



Properties. — They are in general little used for food or in the arts. Their coarse herbage is often eaten 

 by cattle, but they are nearly destitute of the sweet and nutritious properties of the grasses. The leaves 

 ot some of the larger species are used in Italy to bind flasks, and in weaving the bottoms of chairs. 

 Yet, although of so little apparent value, their vast numbers authorize the belief that they subser^'e 

 many highly important ends in the economy of nature. 



Conspectus of the Genera. 



("Flowers in axillary, racemose spikelets DuUchium. 1 



. . J ( Spikelets linear, many-flowered, distinct, loose. Cyperus. 2 



distichously 1 < J Ach. triangular. Mariscus. 3 



imbricated. I Fls. all terminal. ( Spikelets 1—2-flowered, in hds. ? Ach lenticular. KylUngia. 4 



f Perigynium of 3 ovate, unguiculate petals, with 3 bristles. Fuireria. S 



I Leaves 0. Spike solitary, terminal. . Eleocharis. 6 



[■ Bristles 3 — 6 Scirpus. 7 



J Bristles numerous, long. . Eriophoruin. 8 



Leaves 1 ^ Style 2-clett. . Fimbristylis. 9 



present. . (. Bristles 0. ( Style 3-cleft. . Trichetostylis. 10 



4 Bristles 3—6. Sty. deciduous. Scirpus. 7 



Flowers all lateral. ( Bristles o. Leaves radical. . Heniicarpha. 11 



\ Style short, bulbous at base. Rhynchospora. 13 



Flowers TBrist. 3 — 6. ( Style very long, hom-like. . CeratoschcBnus.U 



both I ( Spikelets 20— 30-flowered. . Psilocarya. 12 



axil.and 1 -4 Spikelets S Ach. corky, brown. Cladium. 15 



. .- Jermin. I, Bristles 0. ( few flwrd. < Ach. bony, white. Scleria. 16 



imbricated. ( Achenium enclosed in a saccate perigynium. Fls. declinous. . Carex. 17 



Tribe 1. CYPERE^. — Flowers ^ . Spikelets distichously imbricated. 

 1. DULICHIUM. 



Gr. 6voi, two, \ei)(^r!v, scale; alluding Ui the glumes in two rows? 



Spikelets linear-lanceolate, subcompressed ; glumes sheathing, 

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

 crowning the compressed achenium ; ovary invested with setas. — 

 Stem leafy. Spikes axillary, racemose. 



D. spATHACEUM. Pers. (Cyperus. Linn. Scirpus. Michx.) 

 St. round, leafy and somewhat 3-sided abore, thick, sheathed below; lvs. 

 alternate, pointing 3 ways, 2 — 4' by 3" ; sheaths tubular, shorter than the inter- 

 nodes; spikes axillary from within the sheaths and terminal, each consisting 

 of 8 — 10 linear-lanceolate, alternate spikelets in 2 rows ; spikelets 5 — 7-flowered, 

 nearly an inch in length ; glumes linear-lanceolate. — % Marshes, borders of 

 streams, U. S. and Can. Aug. 



2. CYPERUS. 

 Spikelets compressed, distinct, many-flowered ; glumes imbricated 

 in two, opposite rows, nearly all with a flower enclosed ; ovary generally 

 without setae. — Mostly %. Stem simple, leafy at base, mostly triangii- 

 lar, hearing an involucrate, simple or compo mid umbel at top. 



spirally or ( Ach. not 

 irregularly < enclosed 



