C"SPEEACEAE. 57 



1. Schoenus nigncans L. Sp. PI. 43. 1753. 



Glabrous; culms 2-7 dni. tall, mostly longer than the leaves. Leaves 

 similar to the culm, stiff, sharp-pointed, semiterete, 0.5-1.5 mm. thick, their 

 bases dark brown or nearly black, shining; involucre of 2 bracts, one of them 

 elongated, sometimes 8 cm. long; spikelets about 1 em. long in a dense, ter- 

 minal, capitate cluster, 5-8-flowered, compressed, their scales dark chestnut- 

 brown, or nearly black, lanceolate, carinate, acuminate, somewhat shining; 

 perianth-bristles 6, plumose; aehene ellipsoid, white, shining, about 2 mm. long; 

 shorter than the bristles. 



Swamps, Andros, New Providence, Eleuthera, Crooked Island, Caicos : — Flor- 

 ida ; Cuba ; southern California ; Europe. Black-headed Sedge. 



11. SCLERIA Berg. Vet. Acad. Handl. 26: 142. 1765. 



Leafy sedges, mostly perennial, the spikelets small, clustered in terminal, 

 or terminal and axillary fascicles, or sometimes interruptedly spicate. Flowers 

 monoecious. Fertile spikelets 1-flowered. Staminate spikelets many-flowered. 

 Scales imbricated, the 1-3 lower and sometimes also the upper ones of the fertile 

 spikelets empty. Perianth none. Style 3-cleft, slender or sometimes swollen 

 at the base, deciduous. Ovary supported on a disk (hypogynium), or this 

 wanting. Stamens 1-3. Aehene globose or ovoid, obtuse, crustaceous or bony, 

 white in our species. [Greek, in allusion to the hard fruit.] About 200 

 species, natives of tropical and temperate regions. Type species: Scleria 

 Flagellum-nigrorum Berg. 



Annual ; aehene with sharp transverse ridges. 1. S. verticillata. 



Perennial ; aehene smooth. 2. ij'. Uthosperma. 



1. Scleria verticiUata Willd. Sp. PI. 4: 317. 1805. 



Eoots fibrous; culms very slender or filiform, 3-angled, smooth or nearly 

 so, erect, 1-5 dm. taU. Leaves very narrowly linear, 0.5-1 mm. wide, erect, 

 shorter than the eulm; spikelets in several separated clusters; bracts bristle- 

 like; scales glabrous; aehene globose, 1 mm. in diameter, crustaceous, marked 

 by sharp distinct tranverse ridges, or somewhat reticulated; hypogynium none. 



Borders of marshes, Kew Providence : — eastern United States ; Cuba. Low 



XUT-KUSH. 



2. Scleria lithosperma (L.) Sw. Prodr. 18. 1788. 



Scirpus liihospermus L. Sp. PI. 51. 1753. 

 Scleria fiUformis Sw. Prodr. 19. 17SS. 



Perennial by rather short rootstocks, the culms often clustered, slender, 

 weak, glabrous, 2-6 dm. long. Leaves 0.5-3 mm. wide, the upper elongated, 

 the lowest reduced to pubescent or puberulent sheaths; panicles 1-3, distant, 

 glabrous, small, stalked or the upper sessile; bracts filiform, glabrous; aehene 

 obovoid-ellipsoid, white, smooth, shining, about 2 mm. long, its bas& trigonous ; 

 hypogynium none. 



Coppices and sernb-lands, Abaeo, Great Bahama, Berry Islands and Andros 

 to Marihuana and Inagua : — Florida ; West Indies ; continental tropical America ; 

 Old World tropics. Slesdee Nut-eusb. 



