Rhynchospora. 



CYPERACE^E. 



365 



5. Rhynchospora glomerata, Vahl. Common Beak-rush. 



Culm obtusely triangular ; leaves flat; spikelets ovoid -oblong, in corymbose fasciculate 

 clusters which are terminal and axillary, distant, often in pairs ; achenium smooth, obovoid- 

 lenticular, margined, attenuated at the base, as long as the tubercle ; bristles 6, retrorsely 

 hispid, about as long as the achenium and lanceolate tubercle. — Vahl, enum. 2. p. 234 ; 

 Pursh, fl._ 1. p. 48 ; Ell. sk. 1. p. 61 ; Torr. fl. 1. p. 55 ; Beck, hot. p. 428 ; Darlingt. 

 fl. Cest p. 24 ; Gray, Rhynch. I. c. no. 29, and in Torr. Cyp. p. 367 ; Kunth, enum. 2. 

 p. 296. R. capitellata, Vahl, I. c. ; Ell. I. c. Schcenus glomeratus, Linn. sp. 1. p. 44 ; 

 Muhl. gram. p. 8. S. capitellatus, Michx. fl. 1. p. 36. 



Culm 1-2 feet high. Leaves rough on the margin. Heads of spikelets on included or 

 somewhat exserted peduncles. Scales lanceolate, mucronate, brownish. Bristles stout. 

 Stamens 3. Achenium attenuated into a short thick stipe, smooth and somewhat polished. 

 Tubercle subulate-lanceolate, compressed, about as long as the achenium. 



Bogs and low grounds : common. Fl. July - August. Fr. August - September. 



6. Rhynchospora cephalantha, Gray. Round-headed Beak-rush. 



Heads somewhat globose, dense, many -flowered, axillary and terminal, often in pairs ; 

 spikelets oblong-lanceolate ; achenium smooth, orbicular-obovate, margined, narrowed at the 

 base, about as long as the subulate beak, and half the length of the stout hispid bristles. — 

 Gray, Rhynch. I. c. no. 30, and in Torr. Cyp. p. 368 ; Kunth, enum. 2. p. 540. 



Culm obtusely triangular, rather stout. Leaves narrowly linear, flat, keeled. Heads mostly 

 2-3 (rarely more except in the Southern States) ; the upper 2 often in pairs, from one half 

 to three fourths of an inch in diameter. Scales dark brown, oblong, acute or slightly mucronate. 

 Bristles mostly hispid downward, but often upward, sometimes in the same spikelet ! Ache- 

 nium nearly twice as large as in R. glomerata, but resembling it in form and in the tubercle, 

 shining, obscurely waved transversely. 



Sandv swamps. Islip, &c. Long Island. Fl. August. Near the preceding species, but the 

 heads are larger and compact ; the achenium also is larger, and the tubercle broader. 



