Cypcrus. CYPERACEyE. 213 



« Flowers nil perfect : spikclets few- many- flowered, solitaiy or spicate, the spikes capitate or 



vinibellatti : only 1 or 2 of the lower scales usually empty. 

 +- Spikelets more or less flattened, the scales being in 2 ranks : inflorescence involucrate. — 



Cypeue/e. 



1. Cyperus. Perianth (bristles, etc.) none. Style slender, deciduous. Sjiikelets spicate or 



clustered. 

 DliF.if.'linrM Hi'ArilACF.iT.M, Pors. (the only species), distiuf^uished by its very leafy jointed 

 fitems and axilliiry solitary peduncles bearing .sessile many-flowered spikelets, and by the linear- 

 oblong nutlet acute witii the base of the long 2-cleft style ami surrounded by (i to 9 ri'trorsely 

 barlied bristh's, occurs on thi- Columbia iiivcr and is common in the Atlantic States. Tiie erect 

 terete hollow culm is nearly covered by the sheaths of the short flat linear o-ranked leaves (the 

 lower sheaths without blades) ; spikelets in a 2-ranked sjiike, linear-lanceolate, the naked rha- 

 chis articulateil at the base of each scale. 



-1- +- Spikelets many-flowered, not flattened, the scales imbricated all around. — Sciri'E.e. 

 ++ Stylo not dilated at base. 



2. Scirpus. Spikelets .solitary or clustered, or in a compound umbel, the stem often leafy at 



base and inflorescence involucrate. Style deciduous or only the base persistent. Barbed 

 biistles ))resent at base of the nutlet or wanting. Stamens mostly 3. Perennials. 



3. Eriophorum. As Scirpii.i, but the numerous naked bristles long-exserted and silky in fruit. 



Spikelets few. Stamens 1 to 3. Perennial. 



4. Heniicarpha. As Srirpu.';, but without bristles and with a minute hyaline bractlet between 



each flower and the rhachis. Spikelets solitary or few in a sessile apparently lateral clus- 

 ter. Stamen 1. Low annuals. 



++ +t Style enlarged at base. 



5. Eleocharis. Spikelet solitary, terminal u})on a leafless bractless stem. Base of the style 



persistent. Bristles usually jjresent. Stamens 3. 



6. Fimbristylis. Spikelets in an involucrate umbel. Stem leafy at base. Style usually wholly 



deciduous. Bristles none. Stamens 1 to 3. Perennials. 

 • » Spikelets polygamous, few-flowered, ovoid or oblong-ovoid, the scales loosely imbricate all 

 around, only the terminal ones fertile. — Kiivnciiospore.e. 



7. Cladium. Spikelets in cyme-like panicles. Stems tall, leafy. Bristles none. Style not en- 



larged at base, deciduous. Nutlet corky at the apex. Stamens 2. Perennial. 

 PnvNCiiosponA, Vahl, is distinguished from Cladium by the presence of bristles and the nutlet 

 crowned by the persistent tuberculate base of the style. \\. AMiA, Vahl, has been collected in 

 Oregon (//"//), a slender species with narrowly linear leaves, the lanceolate tawny spikelets in 

 a close terminal corymb ; perfect flowers 1 or 2, with 3 stamens, 9 to 12 or more bristles minutely 

 barbed downward, and a smooth oblong-obovate nutlet bearing a long flattened awl-shaped tuber- 

 cle. It is connnon eastward and also in Europe. 



« » • Flowers moncecious, in the same or distinct spikelets, or dioecious; pistillate flowers en- 

 closed in an inflated sac-like persistent perigynium. — Carice^. 



8. Carex. Spikelets solitary, spicate or jianiculate. Hypogynous bristles or scales wholly 



wanting or a single short bristle at the base of the ovary. 



1. CYPERUS, Linn. Gaungale. 

 Flowers perfect, in few - many-flowered flattened or sometimes terete spikelets ; 

 the concave more or less carinate scales in 2 ranks, often decurrent npon the rhachis, 

 at length deciduous, 1 or 2 of the lowest usually sterile. Hypogynous scales or 

 hristles none. Stamens 1 to 3. Style not thickened at hase, 2 - 3-cleft, deciduous. 

 Nutlet lenticular or triangular, not beaked, smooth or nearly so. — Perennials or 

 annuals, with mostly triangular and nearly naked simple stems, sheathed at base by 

 the nearly radical leaves ; inflorescence subtended by a mostly conspicuous foliaceous 

 involucre, usually irregidarly umbellate with unequal rays, the spikelets in spikes 

 solitary or clustered upon the rays, the central spike or cluster always sessile, and 

 the whole often contracted into a single nu)re or less den.so head. 



A very large genus, numbering 500 species or more, es]iecially abundant in tropical and sub- 

 trojucnl regions. About 50 species are found within the limits of the United States. Most of the 

 following sections have been ny some authorities regarded as distinct genera. 



