562 CYPERACE;E. 



CXXXVI. CYPERACE.E. 



Flowers in spikelets, naked : the sexual organs often supported by bristles or scales, en- 

 closed by glumaceous bracts (glumes) : bracts usually single at each flower. Stamens often %, 

 hypogyn'ous. Ovary simple: ovule single, erect: style 2-3-cleft. Pericarp utricular. 

 Embryo trochleate, included within the summit of amylaceous albumen. — Habit of grasses, 

 but stem solid, devoid of tumid nodes, leaves tristichous, and their sheath mostly closed. 



Tbibe I. CYPERE2E. — Flowers distichous, hermaphrodite. 



1. CYPERUS, L. 



Spikelets many-few-flowered : 1-2 lowest glumes empty : rhachis furrowed, often winged 

 at each internode by the decurrent, at length lacerate part of the glumes. Achenium beak- 

 less. — Spikelets clustered or spikate, rarely solitary : the clusters often in a simple or com- 

 pound, terminal, involucrate umbel. 



The description of the form of the glumes regards their conduplicate, keeled state, viz. one- 

 half of their entire breadth. 



Sect. 1. Pvckeus, P. B. — Spikelets compound: furrows narrowly winged : plumes 

 keeled. Style 2-cleft. Achenium laterally compressed. 



1. C. polystachyus, Rottb. Rhizoma short; stem 3-angular, glabrous; umbel 

 usually contracted : involucre long, 3-6-leaved ; spikelets densely clustered, lanceolate, 

 pointed, usually pale, many(-8)-9owered; plumes elliptical-lanceolate, bluntish, '6-nerved 

 at the keel with the midrib excurrent, 4*-3 times as long as the furrow, twice as long as the 

 oblong achenium ; stamens 2-1— Rottb. Descr. t. 11. /. 1.— Stem 1' (8"-2') high, naked 

 above, usually exceeding the flat leaves ; glumes 1'" long. — Hab. Jamaica !, Pd., in moist 

 places ; Antigua !, Wullschl. ; Trinidad !, Cr. ; [all tropical countries to Australia !, the 

 Cape !, Algeria!, and the hot springs of Ischia !]. 



2. C. variegatus, Kth. Rhizoma short ; stem 3-angular, glabrous : clusters in an unequal 

 tfr contracted umbel : involucre long, 3-leaved ; spikelets ovate-oblong or ohlonp-lanceolate, 

 bluntish, either pale or blackish, 14-8(-" 24 ")-flowered ; plumes half-ovate-oblonp, blunt, 

 few-nerved at the keel, 4-5 times as long as the furrow, 2£ times as long as the elliptical 

 achenium; stamens 2(-l). — C. melanostachyus, Kth.: the blackish, C. flavus, Prl.: the 

 yellowish-flowered form, of which the latter is our Jamaica plant, while the former exists m 

 Swartz's West Indian herbarium. — 6"-18"high; glumes V" long. — Hab. Jamaica !, Pd., 

 in the plains of Westmoreland ; [Haiti ! Mexico to Costarica!, New Granadaj. 



Sect. 2. Juncellus. — Spikelets compressed : glumes keeled : furrows narrowly margined. 

 Style 2-cleft. Achenium compressed from the back. 



3. C. xnucronatus, Rottb. Rhizoma creeping ; stem cylindrical below, glabrous, 1- 

 leaved (or naked) ; cluster single i involucre unequally 2-rayed : the lonper ray erect, the 

 inferior shorter than the cluster ; spikelets oblong or ovate, bluntish, pale, many (-6) -flowered ; 

 plumes half-ovate, blunt, 3-4 times as long as the furrow, twice as long as the oval ache- 

 nium ; stamens 3. — Rottb. Descr. t. 8./. 4. — 1£'-6" high; leaves narrow; glumes 1' 

 long. — Hab. Antigua!, Wullschl.; [all tropical countries to Egypt and Pantellaria !]. 



Sect. 3. Eucyperus, Liebm. — Spikelets compressed or subcompressed : plumes keeled: 

 rhachis persistent. Style %-cleft. Achenium %-anpular. 



* Root annual. 



4. C. compressus, L. Annual ; stem 3-angular, glabrous ; clusters umbellate (or 

 single) : involucre long, 3-6-leaved ; spikelets flat-compressed, oblong-linear, pointed, pale, 

 many (--6)-nowered ; glumes half -ovate-oblong , cuspidate with a spreading -erect point, sharply 

 keeled, many-nerved, winged, 4-5 times as long as the furrow, thrice as long as the obovate, 

 3-quetrous, smooth achenium ; stamens 3. — SI. t. 76. /. 1. Rottb. Descr. t. 9. /- 3. — 

 4"-12" high ; leaves narrow, flat, rarely setaceous ; glumes 1£''' long. — Hab. Jamaica !, 



