(nrKItACK.^-:. (SKU(iE FAMILY.) 0G9 



Tribe IV. CARICE^^E. Flowers monoecious in the same (amlrogynous) or In separate 



spikes, or soinelimes dioecious. Achene enclosed in a sac ( pcrir/ynium). 

 IG. Carex. Ilypogynous bristle short and enclosed in the perigyniuin or none. 



1. CYPERUS, Tourn. G.vi.in(;ali:. (PI. 1.) 



Spikelets iiiauy - few-Howered, mostly flat, varitnusly arranged, mostly iu 

 clusters or heads, which are commonly disposed in a simple or compound ter- 

 minal umbel. Scales 2-ranked, couduplicate and keeled (their decurrent base 

 below often formin«; margins or wings to the hollow of the joint of the axis next 

 below), deciduous when old. Stamens 1 -3. No bristles or inner scales. Style 

 2-3-cleft, deciduous. Achene lenticular or triangular, naked at the apex. — 

 Culms mostly triangular, sim])le, leafy at base, and with one or more leaves at 

 the summit, forming an involucre to the umbel or head. Peduncles or 

 rays une(jual, slieathed at base. All flowering in late suinmer or autumn. 

 (KvTrfipo;,t\\e ancient name.) 



§ 1. PYCREUS. Achene lenticular, the edge turned to the rhachis ; spikclet 



Jlattened , manij-flowered ; rhachis narrow, not winged. Annuals. 



* ['label simple or capitate, rarely slightli/ compound. 



1. C. flavescens, L. Culms 4-10' high; spikelets 5-8" long; invo- 

 lucre 3-lcaved, very unequal ; spikelets becoming linear, obtuse, clustered on 

 the 2-4 A-ery short rays (peduncles); scales obtuse, straw-yellow ; stamens 3; 

 achene shining, orbicular, its superficial cells oblong. — Low grounds, N. Eng. 

 to Mich., 111., and southward. (Ku., etc.) 



2. C. diandrus, Torr. (PI. l, fig. 1-4.) Spikelets lance-oblong (3-9"), 

 scattered or clustered on the 2-5 very short or unequal rays ; scales rather ob- 

 tuse, pur pi e-l)r own on the margins or nearly all over; stamens 2, or sometimes 

 3 ; achene dull, oblong-obovale ; otherwise much like the last. — Low grounds, 

 common from the Atlantic to Minn., Ark., and N. Mex. — Var. castAnets, 

 Torr. Scales more firm and browner; with the type. 



3. C. Nuttallii, Torr. Culms 4-12' high; spikelets lance-linear, acute 

 and very flat (^- V long), crowded on the few usually very short (or some of 

 them distinct) rays; scales oblong, i/ellowish-brown, rather loose; stamens 2; 

 achene oblong-rjbovate, veri/ blunt, dull. — Mostly in salt or brackish marshes, 

 along the coast, from Mass. to the Gulf. 



4. C. polystkchyus, Rottb., var. leptostachyus, Boeckl. Culms 

 very slender, G- 15' high ; leaves and elongated involucre very narrow; spike- 

 lets few to many on the 4-8 rays, linear, acute, 2 - 9" long ; scales thin, ovate, 

 acute, closely imbricated, pale brown ; stamens 2 ; achene linear-oblong or clavate, 

 short-pointed, grayish and minutely pitted. (C. microdontus, Torr.) — Margins 

 of ponds and streams, Va. to Fla. and Tex. 



* * Umbel compound. 



5. C. flavicomus, Vahl. Culm stout (1 -3° higli) ; leaves of the invo- 

 lucre 3-5, very long; sjjikelets linear (4-9" long), spiked and crowded 

 on the whole length of the branches of the several-rayed umbel, spreading; 

 scales oval, very obtuse, yellowish and brownish, broudli/ svarious- (whitish-) 

 margined; stamens 3; achene obovate, mucronate, blackish. — Low grounds, 

 Va. to Fla. 



