CYPERACE^E. (SEDGE FAMILY.) 557 



15. CILffiTOSPORA, R. Br. 



Spikes few- (1 -8-) flowered. Scales imbricated in two rows; the lower 

 ones empty, the upper bearing perfect flowers. Perianth of 3-6 scabrous or 

 plumose bristles. Stamens 3. Style 3-cleft, not dilated at the base, nearly 

 deciduous. Nut triangular, mostly pointed by the persistent base of the style. 

 - Leaves radical, narrow. Spikes in a terminal cluster, subtended by a 1 - 2- 

 leaved involucre. 



1. C. nigricans, Kunth. Culms tufted, jointed near the summit ; 

 leaves rigid, erect, semi terete, shorter than the culms; sheaths black; in- 

 volucre 2 leaved, the lower longer than the ovoid dark brown head ; spikes 

 ovate-lanceolate, compressed, 6- 8-nowered ; scales ovate, keeled ; rachis zig- 

 zag ; bristles 6, unequal, dilated at the base, hispid upward, longer than the 

 globose-3-angled white and polished nut. (Schcenus uigricans, L.) Damp 

 soil, chiefly along the coast, Florida. May. Jl Culms 1- 1^ high. 



16. PSILOCARYA, Torr. 



Spikes many-flowered, terete. Scales imbricated in several rows, mem- 

 brauaceous, all bearing perfect flowers. Perianth none. Stamens 2. Style 

 2-cleft Nut biconvex, transversely wrinkled, crowned with the persistent 

 base of the style. Culms leafy. Spikes ovate, disposed in spreading lateral 

 and terminal corymbs. 



1. P. rhynchosporoid.es, Torr. Culms nearly terete (^- 2 high); 

 leaves narrowly linear, longer than the culm ; corvmbs 2 - 3, widelv spread- 

 ing, the terminal one mostly compound; spikes pedicelled ; scales ovate, 

 acute; nut orbicular, strongly wrinkled ; tubercle compressed, very short, ses- 

 sile, but. not decurrent on the edges of the nut. (Scirpus niteus, Vahl.) 

 Shallow pine barren ponds, Florida to North Carolina. July. (T) Culms 

 commonly rooting at the lower joints. 



2. P. corymbiformis, Benth. Corymbs less spreading ; scales of the 

 spikelets thinner and narrower, obtuse ; nut faintly wrinkled ; tubercle tri- 

 angular, acuminate, as long as the nut ; otherwise like the preceding. 

 Georgia, Florida, and westward. 



17. DICHROMENA, Kichard. 



Spikes compressed, few-flowered, aggregated in a terminal head, and sur- 

 rounded by an involucre of several leaves, which are commonly white at the 

 base. Scales imbricated in two rows, most of them bearing abortive flowers. 

 Stamens 3. Style 2-cleft. Nut lenticular, crowned with the broad and per- 

 sistent base of the style. Perianth none. Perennials. Culms jointless, leafy 

 at the base. Scales white, membranaceous. 



1. D. leucocephala, Miohx. Culms (l-Hhigh) slender, 3-angled ; 

 leaves narrowly linear; involucre of 4-7 narrow leaves; nut orbicular, 

 wrinkled; tubercle flat, broadly conical, sessile, but not decurrent. Damp 

 soil, Florida to North Carolina. August -Sept. Involucre unchanged in 

 drying. 



