SCIRPUS. CLX. CYPERACE^E. 571 



almost capillary, 2 4f long ; spike solitary, somewhat terminal (the stem being 

 continued above it in the form of a bract), lanceolate ; style deleft ; bristles 6. 

 Streams, &c., Mass. ! to N. Y. Aug. 



3. S. CJESPITOSUS. Bracted Mountain Rush. 



Sis. ccespitose, round, sheathed at base with numerous rudiments of leaves ; 

 spikes compressed, terminal ; 2 lower glumes involucre-like, as long as the spike ; 

 ach. with 6 bristles. Grows in dense tufts, 4 12' high. Spike 4 5-flowered, 

 reddish-brown. On the White Mts., N. H., Bw. July. 



4. S. ROBBINSII. (auct.?) 



St. 12 18' high, soft, loosely cellular, terete, leafy at base ; Ivs. submersed, 

 shorter than the stems, very narrowly linear, loosely cellular ; spike broad-ovate, 

 3 4" long, placed about 6" below the ape"x of the stem ; glumes loose, 10 13, 

 ovate, acute, green ; bristles 3 6, shorter than the achenia ; ach. globose-ovoid, 

 biconvex, smooth, of a dull brown, with a slender, conspicuous beak. Ponds, 

 "Oxbridge, Mass., Dr. Bobbins I 



* * Spikes many, lateral. 



5. S. DEBILIS. Pursh. Weak-stemmed Rush. 



St. csespitose, roundish, deeply striate, 9 16' high, with a few subulate 

 leaves at base; spikelets about 3, short-ovoid, sessile, crowded, subterminal; 



flumes ovate, obtuse, carinate, pale green ; ach. obovate, mucronate ; bristles 4 

 . Borders of ponds and rivulets, N. Eng. to Car. Aug. 



6. S. TRIQ.DETER. Michx. (S. Americanus. Pers.) Three-cornered Rush. 

 St. nearly naked, 3-angled, corners acute and two of the sides concave, 



about 3f high and ending in a sharp point ; Ivs. few and short, from the top of 

 the sheath ; spikes lateral, 1 5, ovate, crowded and sessile, at various distances 

 below the point ; glumes round-ovate, mucronate ; bristles 6. Ponds and marshes, 

 fresh and salt, throughout N. America. 



7. S. LACUSTRIS. (S. acutus. Muhl.} Lake BuLlrush. 



Scape smooth, leafless, filled with a porous pith, 5 8f high, cylindric, 

 tapering above the panicle, and abruptly ending in a short cusp ; panicle cymose 

 near the top; ped. rough, twice compound; spikelets ovoid, closely imbricate; 

 scales ovate, mucronate, pubescent ; bracts shorter than the panicle. The largest 

 species of bullrush, frequenting the muddy margins of rivers and ponds U. S. 

 to Arc. Am. July. 



8. S. OLNEYI. A. Gr. Olney's Rush. 



St. triquetrous- winged, leafless, 2 7f high ; slieath radical, tipped with a 

 short (12') leaf; spikes 612, sessile, aggregated, 23" long, placed 912" 

 below the triangular apex of the stem ; glumes roundish-ovate, mucronate ; 

 bristles 6 12; ach. obovate, plano-convex, gibbous at apex. Salt marshes, 

 Sekonk river, R. I., Olney ! Tom river, N. Y., Kneiskern. Remarkably distin- 

 guished by its 3- winged stem. July. See also Addenda, p. 638. 



* * * Spikes terminal. 



9. S. MARITIMUS. Sea Bullrush. 



St. acutely 3-angled, leafy, 2 3f high; Ivs. broad-linear, rough-edged, 

 carinate, taller than the stem ; spikes conglomerate, 6 10, nearly an inch long, 

 corymbose ; invol. -of about 3 very long leaves ; glumes ovate, 3-cleft, the middle 

 segment subulate and reflexed ; style 3-cleft ; bristles 3 4, much shorter than 

 the broad-obovate, lenticular, dark brown, polished achenium. Salt marshes, 

 N. Eng. ! to Flor. Aug. 



p.ftuviatilis. Torr. Umbel somewhat compound; bristles 6, as long as the 

 obovate, triangular, dull grayish achenium. Fresh water swamps and lakes, 

 Western N. Y. to Wis., Laphaml and Mo. 



10. S. ATROVlRENS. Muhl. 



St. obtusely triangular, leafy, 2f high ; cyme compound, proliferous ; invol. 

 of 3 leaf-like bracts, longer than the cyme ; spikes ovate, acute, crowded, 10 20 

 in a globose head; hds. numerous, -' diam., dark green; glumes ovate, mucro- 

 nate ; ach. white, smooth ; bristles 4. Common in meadows, Middle and Western 

 States. June, July. 



