570 CLX. CYPERACE^:. SCIRPUS. 



69' long ; spike acute, 2 3" long, 7 9-flowered ; glumes lance-ovate, acute, 

 reddish -brown, with a green midvein ; bristles 6, white, longer than the ache- 

 nium ; sty. 3-cleft ; ach. obovate, attenuated to the base, striate, of a light brown 

 color. In running water, forming a strong, dense turf, N. H. ! to Ga., W. to 

 Ohio, July. 



9. E. ACICULARIS. R. Br. (Scirpus. Linn.') Hair Club Rush. 



St. leafless, setaceous, quadrangular, very slender, 3 6' high; spikelets 

 oblong-ovate, acute, 4 8-flowered ; glumes obtusish, the lowest one larger and 

 empty ; ach. obovoid, triangular, verrucose, yellow and shining. Edges of ponds, 

 often partly submersed, U. S. and Brit. Am. Very delicate. June, July. 



10. E. TENUIS. Schultes. (Scirpus. Willd.} Slender Club Rush. 



St. leafless, almost filiform, quadrangular, the sides sulcate, 8 15' high, 

 with a long, purple sheath at base ; spike terminal, elliptic-oval, acute at each 

 end; glumes dark purple, ovate, obtuse, the lower ones larger and empty; ova. 

 roundish, tapering below, in vested with 2 or 3 or setae. Common in wet places, 

 N. Eng. and Mid. States. June, July. 



11. E. MELANOCARPA. Torr. (Scirpus. Baldwin.) Black-fruited Club Rush. 

 Sts. compressed, furrowed, slender, almost filiform, wiry, 12 18' high ; 



sheaths truncate ; spike lance-oblong, rather acute, 4 6" in length, 20 40-flow- 

 ered ; glumes ovate, obtuse, brownish, with scarious margins and a prominent, 

 yellowish midvein ; bristles 3, purple ; ach. obovate-turbinate, blackish ; tubercle 

 broad, flat, pointed in the centre. Providence, R. I., Olney ! 



12. E. PIGM.EA. Torr. 



St. 12' high, setaceous, compressed, sulcate; spikes ovate, compressed, 

 3 6-flowered, mostly empty ; bristles 6, longer than the achenium, slender, 

 scabrous backwards ; ach. ovate, acute, triangular, whitish and shining ; tuber- 

 cle minute. Sea coast, Mass., Oakes. Sept. (Dr. Sartwell, comm.) 



13. E. ROSTELLATA. Torr. inN. Y. Fl. ined. (Scirpus. Torr. Cyp.,p. 318.) 

 St. 15 20' high, clustered, angular and sulcate, slender, almost filiform, 



rigid ; sheaths obliquely truncate, the lowest blackish at summit ; spike laiice- 

 ovate, acute, 3 4" long; glumes 12 20, lance-ovate, smooth, light brown, edge 

 scarious ; bristles 4 6 ; ach. broadly obovate, biconvex, light olive-brown, with 

 a long, slightly tuberculate beak. R. I., Olney ! N. Y., Sartwell. 



14. E. COMPRESSA. Sullivant ! Flat-stemmed Club Rush. 



St. 12 18' high, caespitose, much compressed, narrowly linear, striate ; 

 sheath close, truncate ; spike oblong-ovate, 3 5" in length, 20 30-flowered ; 

 glumes ovate-lanceolate, acute, mosily 2-cleft at apex, dark purple on the back, 

 with a broad, scarious margin ; bristles 0; ach. obovate-pyriform, shining, mi- 

 nutely punctate, of a light, shining yellow, the minute tubercle fuscous. Wet 

 places, near Columbus, Ohio ! A very remarkable species. 



7. SCIRPUS. 

 Celtic cirs, the general name for rushes. 



Glumes imbricated on all sides ; perigynium of 3 6 bristles, per- 

 sistent ; sty. 2 3-cleft, not tuberculate at base, deciduous ; achenium 

 biconvex or triangular. ^1- Stems mostly triquetrous, simple, rarely 

 lea/less. Spikes solitary, conglomerated or corymbose. 



1. Bristles not exceeding- the achenium, retrorsely denticulate. 

 * Spike solitary, nearly or quite terminal. 



1. S. PLANIFOLIUS. Muhl. Flat-leaved Club Rush. 



St. caespitose, leafy at base, acutely and roughly 3-angled, 510' high ; 

 Ivs. broad-linear, flat, rough on the margin, equaling the stem; spike oblong- 

 lanceolate, compressed, terminal, 4 8-flowered ; glumes ovate-mucronate, yel- 

 lowish ; bracts at the base of the spike, cuspidate, outer ones longer than the 

 spike; ach. reddish-brown, invested with 6 bristles longer than itself. In cold, 

 hard soils, Mass., Robbins ! N. Y. to Del. June. 



2. S. SUBTERMINALIS. Torr. 



St. floating, furrowed, inflated, leafy below, 3f long ; Ivs. very narrow, 



