184 FLORA. 



some species by the whole style. [Greek, referring to the beak-like tubercle.] 

 About 200 species, of wide geographic distribution, most abundant in warm re- 

 gions. Besides the following, some . 7 others occur in the southern U. S. 



Style entire or 2-toothed, persistent as a long-exserted subulate beak. 



i. R. corniculata. 

 Style deeply 2-cleft, only its base persistent as a tubercle. 



Bristles minute or wanting. 2. R. pallida. 



Bristles plumose. 3. R. oligantha. 



Bristles downwardly barbed or rarely smooth. 



Scales white or nearly so ; bristles 9-15. 4. R, alba. 



Scales brown ; bristles 6. 



Leaves filiform ; achene oblong. 5. R. capillacea. 



Leaves narrowly linear, flat ; achene obovate. 



Bristles equalling the achene ; tubercle one-half as long or less. 



6. R. Knieskernii. 

 Bristles reaching or exceeding the end of the tubercle, which is as long 



as the achene. 

 Spikelets few-several in numerous rather loose clusters. 



7. R. glomerata. 

 Spikelets very numerous in 2-6 very dense globose heads. 



8. R. axillaris. 

 Bristles upwardly barbed. 



Spikelets very numerous in 2-6 very dense globose heads. 8. R. axillaris. 

 Spikelets few-several in rather loose clusters. 

 Achene smooth. 



Leaves setaceous ; achene obovate, shining. 9. R.fusca. 



Leaves narrowly linear, flat ; achene broadly oval, dull. 



jo. R. gracilenta. 

 Achene transversely wrinkled. 



Spikelets ovoid, in erect cymose clusters ; achene longer than the 



bristles. 



Leaves flat ; spikelets nearly or quite sessile. n. R. cymosa. 

 Leaves involute ; spikelets distinctly pedicelled. 



12. R. Torreyana. 



Spikelets spindle-shaped, in drooping panicles; achene shorter than the 

 bristles. 13. R. inexpansa. 



1. Rynchospora corniculata (Lam.) A. Gray. HORNED RUSH. (I. F. f. 

 648.) Culm triangular, smooth, 1-2 m. tall. Leaves flat, 1.5-4.5 dm. long, 6- 

 16 mm. wide, rough -margined; umbels sometimes 2.5 dm. broad; spikelets spindle- 

 shaped, 8-12 mm. long in flower, capitate at the ends of the rays and raylets; 

 primary rays sometimes 15 cm. long; scales lanceolate, thin, acute, light brown; 

 bristles about 6, rigid, upwardly scabrous; style subulate, entire or minutely 

 2-toothed at the apex, 2-4 times longer than the achene, upwardly scabrous, 

 1-2.5 cm - l n g' mucn exserted beyond the scales when mature; achene obovate, flat, 

 4 mm. long, dark brown, smooth. In swamps, Del. to Fla., Ohio, Mo. and Tex. 

 July-Sept. 



Rynchospora cornicul&ta macrostichya (Torr.) Britton. Bristles about twice as 

 long as the achene. Range of the type, but extending north to Mass. 



2. Rynchospora pallida M. A. Curtis. PALE BEAKED-RUSH. (I. F. f. 649.) 

 Rootstocks slender ; culms triangular, 0.3-0.6 m. tall. Leaves 1-2 mm. wide, 

 nearly smooth, the lowest reduced to scales ; spikelets numerous, spindle-shaped, 

 4-6 mm. long, aggregated in a compound terminal head, or occasionally also in a 

 cluster from the upper axil; uppermost leaves subulate; scales pale greenish brown, 

 lanceolate, acuminate ; bristles minute and early deciduous, or wanting; style 2- 

 cleft ; achene lenticular, obovate-oblong, smooth, brown, shining, I mm. long, 

 tipped by a short tubercle. In pine-barren bogs, N. J. to N. Car. Aug.-Sept. 



3. Rynchospora oligantha A. Gray. FEW-FLOWERED BEAKED-RUSH. (I. 

 F. f. 650.) Rootstocks short ; culms almost thread-like, leafy toward the base, 

 1.5-4 dm. tall. Leaves filiform ; spikelets 1-4, terminal, narrowly oblong, acute, 

 6-8 mm. long, subtended by I or 2 filiform bracts; scales ovate, pale brown, acute, 

 cuspidate ; bristles usually 6, densely plumose below the middle ; style 2-cleft ; 

 achene obovoid-oblong, obtuse, pale brown, dull, transversely wrinkled ; tubercle 



