738 ORDER 1 55. CYPERACE^E. 



narrowly linear, striate; sheath close, truncate; spike oblong-ovate, 3 5" in 

 length, 20 30-flowered ; glumes ovate-lanceolate, acute, mostly 2-clet't at apex, 

 dark purple on the back, with a broad, scarious margin ; bristles ; ach. obovate- 

 pyriform, shining, minutely punctate, of a light, shining yellow, the minute tubercle 

 fuscous. Wet places K Y. to 111. 



17 E. acicularis R. Br. Culm leafless, setaceous, quadrangular, very slender, 

 36' high; spike compressed, oblong-ovate, acute, 4 8-flowered; glumes ob- 

 tusish, the lowest one larger and empty; ach. obovoid, triangular, striated length- 

 wise. Edges of ponds, often partly submersed, U. S. and Brit. Am. Very deli- 

 cate. June, July. 



18 E. pigmgea Torr. Culm 12' high, setaceous, compressed, sulcate ; spikes 

 ovate, compressed, 3 6-fld. ; gl. mostly empty; bristles 6, longer than the 

 achenium, slender, scabrous backwards; ach. ovate, acute, triangular, smooth, not 

 striate, whitish and shining ; tubercle minute. Sea coast, Mass., to Fin. and La. 



19 E. microcarpa Torr. Culm capillary, 4-angled, 5 to 8' long; spike oblong, 

 compressed, 10 to 20- flowered, about 2" long, often proliferous; glumes ovate, 

 acutish, keeled, chestnut brown, the lowest much the largest, bristles 3 to 5, 

 shorter than the achenium which is minute, smooth, whitish, with a very minute 

 tubercle. Wet places, N. J., also La. 



20 E. prolifera Torr. Culms capillary, 4-angled and furrowed, 4 to 12' long, in 

 dense tufts; spike minute, 1 to 2" long, compressed, 4 to ^-flowered; glumes ovate, 

 chestnut brown, with scarious margins, often proliferous, that is, producing new 

 culms instead of flowers ; bristles 3 or 4, much shorter than the achenium which 

 is 3-angled and with a broad, depressed tubercle. Fla. ! to La. (Hale). (Chseto- 

 cyperus Baldwinii Torr.) 



6. SCIR'PUS, L. CLUB-RUSH. BULLRUSH. (Celtic cirs, the general 

 name for rushes.) Glumes imbricated on all sides ; perigynium of 3 6 

 bristles, persistent; sty. 2 3-cleft, not tuberculate at base, deciduous; 

 achenium biconvex or triangular. 2 Stems mostly triquetrous, simple, 

 rarely leafless. Spikes solitary, conglomerated or corymbous. 



SCIRPUS. Bristles retrorsely denticulate, about equaling the achenium. (*) 



* Spike single, terminal, with a .short, erect bract at its base Nos. 13 



* Spikes several or many clustered on each culm, (a) 



a Clusters of spikes lateral on the terete, leafless culm Nos. 4, 5 



on the triangular culm Nos. 68 



a Clusters of spikes terminal, mostly umbellate, (b) 



b Glumes lacerately 3-toothed. Spikes large (9 to 12" Ions) Nos. 9, 10 



b Glumes entire. Spikes small (1"), collected in globular heads. . . .Nos. 11. 12 



Spikes small (2 to 8" long), separate N No. IS 



TRICOPHORTJM. Bristles 6, tortuous, tawny, much longer than the achenium, nnd 



exserted. Stem (culm) leafy. Umbel decompound. .". Nos. 14. 15 



1 S. planifolius Muhl. Culm ccespitous, leafy at base, acutely and roughly 3- 

 angkd, 5 10' high; Ivs. broad-linear, flat, rough on the margin, equaling the 

 stem; spike oblong-lanceolate, compressed, terminal, 4 8-flowered; glumes ovate- 

 mucronate, yellowish ; 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. Culm floating, furrowed, inflated, leafy below, 1 to 3f 

 long; Ivs. very narrow, almost capillary, 2 to 4f \ong; spike somewhat terminal 

 (the stem being continued above it in the form of a bract), lanceolate; style 2-cleft; 

 bristles 6. Streams, &c., Mass, to K Y., Mich. Aug. 



3 S. caespitosus L. Culm axspitous, round, sheatlied at base with numerous ru* 

 diments of leaves ; spikes compressed, terminal; 2 lower glumes involucre-like, as 

 long as the spike; ach. with 6 bristles. Grows in dense tufts, 412' high. Spike 

 4 5-flowered, reddish-brown. On the alpine summits of Mts., N. States. Jl. 



4 S. de"bilis Pursh. Culm csespitous, roundish, deeply striate, 9 to 16* high, with 

 a few subulate leaves at base ; spikekts about 3, short-ovoid, sessile, crowded, 

 lateral, the culm continuing a fourth of its length above them, glumes ovate, obtuse, 

 carinate, pale green ; ach. obovate, mucronate ; bristles 4 or 5. Borders of ponds 

 and rivulets, N. Eng. to Car. Aug. 



