30 CYPEBACEAE. 



7. STENOPHYLLTJS Raf. Scapose tufted herbs. Leaves basal: blades 

 narrowly linear, filiform or setaceous, the sheaths ciliate or pubescent. Spike- 

 lets umbellate, capitate, or solitary, the scales spiral, mostly de.-iduous. 

 Involucre of 1-several bracts. Flowers perfect. Perianth none. Style gla- 

 brous, the base much swollen and persistent as a tubercle on the n.'hene. 



Leaf-blades erlllnte : m-henea about 1 mm. long. 1. 8. coarctatu*. 



Leaf-blades dilate : achenes about 0.5 mm. long. 2. 8. Carteri. 



1. S. coarctatus (Ell.) Britton. Scapes 2-3 dm. tall, smooth: umbel con- 

 tracted: spikelets linear-oblong, 10-1 5- flowered: achenes obovoid, about 1 mm. 

 long. Pinelands. 



2. S. Carter! Britton. Scapes 1-1.5 dm. tall, scabrous near the top: umbel 

 not contracted: spikelets ovoid or nearly so, few-flowered: achenes broadly 

 obovoid, about 0.5 mm. long. Pinelands. 



8. DICHEOMENA Miehx. Caulescent herbs with the spikelets crowded 

 in a terminal head involucrate by several bracts, which are often white at the 

 base. Spikelets compressed, several-many-flowered. Scales spirally imbri- 

 cate all around, several of them with imperfect flowers, or empty. Perianth 

 none. Style subulate. Achene lenticular, transversely rugose, crowned \vith 

 the broad persistent base of the style (tubercle). WHITE-TOP. 



Bracts of the Involucre 4-6. linear: tubercle truncate on top of the notion*-. 

 Leaves filiform above the dilated base: achenes dark; tubercle low. blunt 



1 . /). floridtntte. 

 Leaves linear above the dilated base: achenes pale; tubercle 



long, acute. 2. D. roloratn. 



Bracts of the involucre 7-10, lanceolate: tubercle decurrent on the 



sides of the acbene. 3. D. lattfoUa. 



1. D. floridensis Britton. Stems copiously tufted, 2-4 dm. tall, slender: leaf- 

 blades involute-filiform: bracts of the involucre attenuate: heads about 1 <-m. 

 in diameter: spikelets oblong: scales pale: achene-body obovoid, slightly o\er 

 1 mm. long, dark-brown, finely wrinkled. Pinelands. 



2. D. colorata (L.) A. Hitchc. Stem slender, rather sharply triangular. 3-6 

 dm. tall: leaf-blades narrowly linear, much shorter than the stem : bracts of 

 the involucre reflexed when mature, yellowish-white at the base: head globose, 

 1 L' mi. in diameter: spikelets narrowly oblong, an. 1 .mbranmis 

 lanceolate, nearly white, subacute: achene-body obovoid, a little over 1 mm. 

 long, pale-brown, compressed. Everglades and low pinelands. F. K. (Ber., 

 Bah., Cvba, Ant.) 



3. D. latifolia Baldw. Similar to No. 2, but stem stouter, obtusely triangular 

 or nearly terete: leaf-blades lanceolate or linear-lanceolate, tapering gradually 

 to a long acuminate apex from a broad base, 3-8 mm. wide, son- 

 topping the stem: bracts of the involucre strongly reflexed when old: head 

 globote, 1-2 cm. in diameter: spikelets oblong, subacute: scales ovate 1 



late, nearly white, rather obtuse: achene-body nearly orbicular in outline, a 

 littl.- over 1 mm. long, pale-brown, faintly wrinkled transversely and longi- 

 tudinally so as to appear reticulated. Everglades. 



9. 8CHOENU8 L. Acauleseent rush-like herbs. Leaf-sheaths dark-col- 

 ored; blades resembling the scapes, half-terete. Spikes in a terminal .-linter. 

 1-8-flowered, subtended by an involucre of 1-2 bracts. Spikelets crowded, 

 often dark-colored: scales imbricate in 2 rows, persistent Perianth of 3-6 

 scabrous or plumose bristles. Styles barely enlarged at the base, almost 

 wholly deciduous. Achene 3-angled, smooth. 



