524 CYrF.RACK.i:. (sedge famii-y.) 



of the style (tulierclcd). rercniiiiils, witli jointed ami Icafv culms. Spikes 

 Email, disposed in axillary and terminal coryml)S or (•lii.-t<'rs. 



k, I. EHIOCILETE. Bristles of the perianth G, plumose. 



1. R. plumosa, Ell. Culms (6' -12' hi;,'h) and leaves filiform; spikes 

 few, in about three small clusters at the summit of the culm ; nut nearly ;:lohu- 

 lar, strongly wrinkled, pointed with tiie short ovate smooth tubercle ; bristles 

 rather longer than the nut, plumose throughout or nearly to the summit. — Low 

 pine barrens, Florida to North Carolina. June and July. 



Var intermedia. Culms taller (l°-2° high); leaves narrowly linear; 

 elusters 4-6, forming an interrupted spike at the summit of the culm ; nut ol)o- 

 vate, pointed with the conical-beaked pubescent tubercle; i)ristles plumose only 

 at the base, or below the middle. — Sandy pine barrens, often dry places, Florida. 



2. R, semiplumosa, Gray. Culms erect, rigid (l0-2° high); leaves 

 narrowly linear ; spikes oblong-ovate, dark brown, crowded in a terminal head, 

 or rarely in a remote axillary one ; nut globose-obovate, faintly wrinkled, pointed 

 with the short broadly conical smooth tubercle; bristles exceeding the tui)crcle, 

 plumose below the middle. — Dry sandy ridges, near the coast, West Florida. 

 July and Aug. — The leaves, like those of the preceding species, have a joint- 

 like contraction near the middle. 



3. R. oligantha, Gray. Culms (6'- 12' high) and smooth leaves bristle- 

 like, reclining ; corymb terminal, of 3-6 large (4" long) ovate-lanceolate whitish 

 stalked spikes ; niit oval, lenticular, faintly wrinkled ; tubercle dilated at the base, 

 conical, flat; bristles longer or shorter than the nut, plumose below the middle. 

 -^ Low open pine barrens, Florida to North Carolina. June and July. 



^ 2. RIIYXCHOSPORA Proper. Bristles of the perianth 3-20, smooth, 



scabrous, or hispid. 



* Nut transversely icrinlded or uneven : bristles denticulate or hispid upward. 



■*- Bristles shorter than the nut. 



4. R. rariflora, Ell. Culms and leaves bristle-fnrm : corymbs 2 - 3, re- 

 mote, spreading ; spikes few and scattered, ovate ; nut liroadly ol)ovate, bicon- 

 vex, strongly wrinkled, twice as long as the 6 fragile bristles ; tubercle flat, 

 broadly conical, J as long as the nut. — Low grassy pine barrens, Florida to 

 North Carolina. June and July. — Culms 1°-1|° long, commonly reclining. 

 Spikes pedieelled. 



5. R. Torreyana, Gray. Culms erect, slender, nearly terete ; leaves nar- 

 rowly linear or bristle-form ; corymbs 1-3, remote, erect ; nut obovate, flat, about 

 twice as long as the 6 bristles ; tubercle compressed-conical, dilated at the base, 

 J the length of the nut. — Wet ground. South Carolina, and northward. July. 

 — Culm 1°- 3° high. Corymbs many-flowered and somewhat spreading, or 

 few-flowered and capitate. 



6 R. cymosa, Nutt. Culms (2° -3° high) 3-angled ; leaves narrowly 

 linear ; corymbs mostly 3, distant, open or contracted ; spikes ovate, clustered, 

 light brown ; scales mucronate ; nut broadly obovate, biconvex, faintly wrinkled, 

 twice as long as the 3-6 bristles; tubercle broadly conical, compressed, ^ as 



