574 CLX. CYPERACE.^. Rhynchospora. 



12. PSYLOCARYA. Torr. 



Flowers $ . Glumes 00, imbricated all around, all fertile ; peri- 

 gynium ; stam. 2 ; filaments long, persistent ; style 2-cleft, dilated 

 or tuberculate at base ; achenium biconvex, crowned with the per- 

 sistent style. — Stems leaf?/. Spikes lateral and terminal, cymose. 



P. sciRPoiDEs. Torr. 



St. slender, leafy, smooth, 3-sided, 5 — 9' high ; Ivs. linear, smooth, 3 — 5' 

 by 1", cauline about 2 ; cymes terminal, and one from the sheath of each cau- 

 line leaf; spikes about 3" long, oblong-ovate, in small, loose clusters, 20 — 30- 

 flowered ; glumes chestnut-colored, thin, ovate, acute ; ach. tumid, dark brown, 

 crowned with the long style, which is much dilated at base. — Borders of ponds, 

 Smithfield, R. I., Olney ! Mass., Greene. Rare. 



13. RHYNCHOSPORA. Vahl. 

 Gr. pw^og, a beak, a-iropa, seed ; from the character. 



Flowers $ or cJ^ $ 9, few in each spikelet ; glumes loosely imbri- 

 cated, the lowest small and empty; perigynium of 6 — 12 bristles; 

 stam. 3 ; style bifid ; achenium lens-shaped or subglobose, crowned 

 with the distinct, bulbous base of the style. — % Stem leafy, 3-sided. 

 Inflorescence terminal and axillary. 



* Achenium smooth. 



1. R. ALBA. Vahl, (Schoenus albus. Linn.) White Bog- Rush. 



St. triangular above, very slender, leafy, smooth, 10 — 16' high ; Ivs. seta- 

 ceous, channeled ; corymbose fascicles pedunculate, both terminal and from the 

 axils of the sheaths, with setaceous bracts ; spikelets lanceolate, acute at each 

 end, with crowded, lanceolate, white glumes. — In wet, shady grounds ; com- 

 mon. July — Sept. 



2. R. CAPiLLACEA. Torr. (Schoenus. Muhl.) 



St. 6 — 12' high, filiform, glabrous, triangular ; Ivs. setaceous, much shorter 

 than the stem ; spikelets 3 — 6, mostly terminal, oblong, each with a setaceous 

 bract ; glumes chestnut-colored, with scarious edges ; bristles 6, much longer 

 than the oblong, substipitate achenium ; tubercle about half the length of the 

 achenium. — Swamps, N. Y., Sarticcll, Penn., Muhl. 



3. R. FuscA. RcEm. & Schult. (Schoenus fuscus. Linn.) 



St. 3-angled, about 2f high ; Ivs. linear, carinate, smooth ; fascicles alter- 

 nate, pedunculate ; bracts setaceous, longer than the ovoid spikes ; glumes brown, 

 ovate ; ach. brown, rugose, with an acute, black tubercle as long as the hi.spid 

 bristles. — Wet places, Mass. to N. J. Rare, 



4. R. GRACILENTA. A. Gr. 



St. 1 — 2f high, very slender or filiform, smooth; Ivs. linear-setaceous, 

 much shorter than the stem ; corymbs small, fasciculate, the lateral on slender 

 peduncles exserted from the sheaths; spikelets ovoid; glumes ovate, acute, dark 

 brown ; bristles 6, a third longer than the roundish-ovoid achenium ; tubercle 

 flat, dilated at base. — Dry grounds, N. Y. to Car. 



5. R. GLOMERATA. Vahl, (Schoenus. Linn.) 



St. slender, smooth, leafy, a foot or more high ; Ivs. flat, carinate, rougn- 

 edged ; corymled fascicles veiy'remote, in pairs, axillary and terminal ; spikelets 

 lanceolate • gluvies keeled, mucronate, brown ; ach. obovoid or cuneiform, very 

 smooth, as long as the tubercle ; setce 6, rough, backwards. — In bogs. Can. to 

 Flor. July, Aug. 



6. R. CEPHALAXTHA. A. Gr. 



St. 2 — 3f high, triangular, stout ; Ivs. linear, very narrow, the lower and 

 radical nearly as long as the stem; hds. roundish, axillary and terminal, soli- 

 tary or rarely two together ; spikelets lance-oblong ; glumes ovate-oblong, dark 

 brown ; bristles 6, twice longer than the achenium"; ach. roundish-ovoid, a little 

 compressed, very obtuse. — N. J. pine barrens. 



