CYPERACEAE. 29 



barbed, or wanting. Base of the style persistent on the achene as a tubercle. 

 SPIKE-RUSH. 



Spikelet scarcely, If at all, thicker than the scape ; scales leathery. 1. E. cellulosa. 

 Spikelet manifestly thicker than the scape; scales mostly mem- 

 branous. 



Upper sheath scarlous, hyaline : plants perennial. . 2. E. flacdda. 



Upper sheath 1-toothed, not scarlous : plants annual. 3. E. capitata. 



1. E. cellulosa Torr. Perennial. Scapes obscurely 3-angled and invested by 

 discolored sheaths at the base, terete above, 3-7 dm. tall: spikelet cylindric, 

 1.5-3 cm. long: scales with white hyaline margins: achene-body broadly obo- 

 void, copiously pitted, 1.5-2 mm. long, about as long as the bristles; tubercle 

 deltoid, about \ as broad as the widest part of the achene. Everglades. F. K. 

 (Ber., Bah., Cuba.) 



2. E. flaccida (Spreng.) Urban. Scapes very slender, pale-green, 0.5-2.5 dm. 

 tall: upper sheath with a white, hyaline, scarious limb: spikelet subacute, 2-3 

 times as thick as the scape, about 4 mm. long: scales pale-green, hyaline, each 

 with a faint midvein: perianth-bristles about 6, slender, retrorsely barbed, 

 somewhat longer than the achene: achene-body 0.7-1 mm. long, lenticular, 

 obovoid, smooth, brown; tubercle conic, acute. [E. ochreata (Nees) Steud.] 

 Coastal sand-dunes. (Bah., Cuba, Ant.) 



3. E. capitata (L.) E. Br. Scapes tufted, almost filiform, 0.5-2.5 dm. tall: 

 upper sheath 1-toothed: spikelet ovoid, obtuse, much thicker than the scape, 

 3-5 mm. long: scales brown except the greenish midvein, narrowly scarious- 

 margined: perianth-bristles 5-8, slender, downwardly hispid, as long as the 

 achene: achene-body obovoid, jet-black, smooth, shining, 1 mm. long; tubercle 

 depressed, apiculate. Everglades. F. K. (Ber., Bah., Cuba, Ant.) 



5. FIMBEISTYLIS Vahl. Scapose herbs. Spikelets umbellate or capi- 

 tate, terete, several-many-flowered, the scales spiral, all fertile, deciduous. 

 Involucre with 1-many bracts. Perianth none. Style with an enlarged base, 

 but falling away from the top of the achene. 



Achenes cancellate In many rows : style short-clllate. 1. F. castanea. 



Achenes longitudinally ribbed and reticulate : style long-clliate. 2. F. Harperi. 



1. F. castanea (Michx.) Vahl. Plants without scaly rootstocks: leaves few; 

 blades involute, less than 2 mm. wide: scapes 2-5 dm. tall: spikelets oblong, 

 6-10 mm. long: achenes obovoid or oblong, 1.5 mm. long. Everglades. F. K. 

 (Ber., Bah., Cuba.) 



2. F. Harperi Britton. Plants with scaly rootstocks: leaves rather numerous; 

 blades flat or involute, mostly 2-3 mm. wide: scapes 3-6 dm. tall: spikelets 

 cylindric in age, 8-14 mm. long: achenes obovoid or oblong-obovoid, about 1.5 

 mm. long. Coastal sand-dunes. 



6. ABILDGAABDIA Vahl. Acaulescent herbs. Leaf-blades narrow, 

 commonly involute. Scapes tufted, jointless, simple. Involucre of a single 

 small bract. Spikelets solitary or several in terminal umbels or clusters, pale: 

 scales imbricate in 2 rows, or in 3 rows by the twisting of the rachis, deciduous. 

 Perianth wanting. Style pubescent, with a swollen base, deciduous. Achenes 

 3-angled, warty. 



1. A. monostachya (L.) Vahl. Leaf -blades nearly filiform above the dis- 

 colored bases, slightly involute, sharp-pointed: scapes tufted, very slender or 

 filiform, 14 dm. tall, erect, smooth: bracts of the involucre much shorter than 

 the spikelets, inconspicuous : spikelet solitary or sometimes 2 together, flattened, 

 ovoid or conic, 1-1.5 cm. long, pale: achenes slightly pear-shaped, 2-2.5 mm. 

 long, yellowish-white, often apiculate. Pinelands. F. K. (Bah., Cuba, Ant.) 



