CYPERACEAE. 29 



barbed, or wantiug. 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. ccUulosa. 

 Splkelet manifestly thicker than the scape ; scales mostly mem- 

 branous. 



Upper sheath scarious, hyaline : plants perennial. 2. E. flaccida. 



Upper sheath l-toothed, not scarious : plants annual. 3. E. capitate. 



1. E. cellulosa Torr. Perennial. Scapes obscurely S-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 i 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 (i, 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.) R. Br. Scapes tufted, almost filiform, 0.5-2.5 dm. tall: 

 upper sheath l-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. FIMBRISTYLIS 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-ciliate. 1. F. castanea. 



Achenes longitudinally ribbed and reticulate : style long-ciliate. 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. ABILDGAAEDIA 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, 1-4 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.) 



