CYPEEACEAE. 23 



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



Upper sheath 1-toothed, not scarious : plants annual. 



Perianth-bristles 2-4, pale : achenes 0.5 mm.long : scapes 



slender. 3. E. atropurpurea. 



Perianth-bristles 5-8, brown : achenes 1 mm. long : scapes 



almost filiform. 4. E. capitata. 



a I 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 \ as broad as the widest part of the achene. — Low hammocks 

 and lime-sinks, L. keys. — [E. K.] — {Ber., Bah., Cuba.) 



f'l 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 and open hammocks, U. S. keys, U. keys, L. keys. — 

 [E. K.]— (Ba/i., Cuba, Ant.) 



tjS 3. E. atropurpurea (Eetz.) Kunth. Scapes tufted, slender, 2-9 cm. tall: upper 

 ^ sheath 1-toothed: spikelet ovoid, many-flowered, subacute, 3-4 mm. long, 2 mm. 

 in diameter, or less: scales ovate-oblong, persistent, purple-brown except the 

 midvein and very narrow scarious margins: perianth-bristles 2-4, fragile, pale, 

 minutely downwardly hispid, about as long as the achene : achene-body obovoid, 

 jet-black, shining, 0.5 mm. long; tubercle conic, depressed, constricted at the 

 base.- — Open sandy hammocks, L. keys. — {Bah., Cuba, Ant.) 



4. 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. — Sandy places and open hammocks, L. keys. — [E. K.] — 

 {Ber., Bah., Cuba, Ant.) 



^•^ 3. 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. 



^i' 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. — Hammocks and 

 pinelands, U. keys, L. keys. — [E. K.] — {Ber., Bah.) 



'^ -' 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 and open hammocks. — U. S. keys, U. keys, L. 

 keys.— [E. K.] 



4. ABILDGAARDIA Vahl. Acaulescent herbs. Leaf-blades narrow, 

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



