210 



OKDEE CXXXIX. CYPEEACEiE. 



axillary peduncles. Glumes arranged in 2 rows. Perianth 

 reduced to bristles surrounding the ovary. Stamens 3. Style 

 2-cleft above, the lower portion persistent, forming a beak to the 

 compressed achenium. 



1. D. spathaceum. Sheathed Sedge, 



Culm erect, simple, leafy tbrougb the whole length, sheathed below ; leaves 

 alternate, linear, flat, short, arranged on the stem in 3 rows; spikes axillary and 

 terminal, proceeding from the sheaths, consisting of 8 — 12 linear-lanceolate 

 spikelets, loosely arranged in 2 rows; spikelets 5 — 9 flowered, rather long. A 

 common plant along rivers and borders of ponds, 1 — 2 ft. high. Aug. 



8. ele6chaeis. 

 Spikes single, terminal. Glumes imbricated all round with- 

 out much order. Perianth reduced to 3 — 12, mostly 6, rigid, 

 persistent bristles, surrounding the ovary. Stamens 3. Style 2 

 — 3-cleft, bulbous and persistent at base, forming a tubercle 

 crowning the achenium. Culms leafless, simple. 



* Culms rou7idi8h, soft. 



1. E. obtAsa. Sjpike-rush, 



Culms nearly terete in tufts ; epiko more or less globose, at length becoming 

 somewhat cylindrical, obtuse, densely many-flowered; glumes very obtuse, 

 liirht-brown, whitish on the margin; achenium obovate, of a shining brown, 

 surrounded by 6 bristles twice as long as itself, and crowned with a very broad 

 and flat tubercle. A common species in shallow water and muddy grounds. 

 Culms C— 12' high. July—A^tg. 



2. E. palustris. Round Rush. 



Culm nearly terete; spike oblong-lanceolate, acute, manj'-flowered, often 

 obliquely attached ; glumes reddish-brown, whitish on the broad margin ; lower 

 ones sometimes empty ; achenium obovate, surrounded by about 4 bristles 

 longer than itself^ and crowned with a small, ovate, flattened tubercle. A quite 

 variable species; very common in shallow water and low grounds. Culms C 

 — 20' high. June — July. 



* * Culms angular or compressed. 



3. E. tenuis. Slender Rush. 



Culm very slender and wiry, 4-angled, with concave sides ; spike elliptical, 

 somewhat acute at each end, 20—30 flowered ; glumes ovate, obtuse ; achenium 

 obovate, with a email, depressed tubercle, and surrounded by 2 — 1 bristles, or 

 more. A common and very slender species in wet meadows, sufficiently dis- 

 tinguished by its size, and the 4-angled culm ; C — 12' high. June — July. 



4. E. acicularis. Hair Rush. 



Culm setaceous, 4-angled; spike oblong-ovate, 3— 8-flowered; glumes ob- 

 long-ovate, obtusish, purplish on the margin; achenium obovoid-triangular, 

 crowned with a conical tubercle. A very delicate species, common in muddy 

 grounds and edges of ponds, where the culms are as fine as hairs, and 2'— 6' 

 hieh. June— July. 



4. sclEPirs. 



Spikes cylindrical, clustered, and furnished with an involucre, 

 sometimes single, terminal or lateral. Glumes imbricated all 

 round in no fixed order. Perianth reduced to 3 — 6 bristles. 

 Stamens 3. Style 2 — 3-cleft, not bulbous at base, deciduous. 

 Achenium lenticular or triangular. Culms sheathed at base. 

 * Spikes lateral. 

 t Leafless. 



1. S. debilis. Slender Cluh-rush. 



Culms slender, furrowed, tufted, roundish, rarely with a single leaf at base ; 

 spikes few, generally about 3^, ovoid, sessile, in a single cluster situated near 

 the top of the culm, the prolongation of which serves for an involucre ; glumes 

 roundish -ova to, obtuse, pale yellowish-green; style 2 — 3-cleft; achenium 

 obovate, shorter than the 4 — 5 bristles. A slender Rush of a pale-green color, 

 common in wet grounds. Culm G'— 12' high. Aug. 



2. S. lacustris. Bulrush. 



Culm tall, cylindrlc, filled with spongy pith, tapering above, and ending in 

 an abrupt point, dark-green; spikes oblong-ovate, numerous, arranged in a 

 compound panicle somewhat like an umbel, of a reddish-brown color ; glumes 

 ovate, mucronate; acheninm obovate, mucronate, surrounded by 4— 5 bristles. 

 A tall, dark-green Eush, Common in wet grounds, usually leafless, sometimes 

 with a single, subulate leaC Culm 4 — 8 ft. high. July. 

 t + Culm with leaves. 



3. S. pungens. Acute Cluh-rush. 



Culm acutely angled with concave sides ; leaves few, carinate below, chan- 

 nelled above, often 6'— S' long; spikes ovoid, sessile, 1—5 in a cluster, which is 

 much shorter than the involucral prolongation of the stem ; glumes ovate, 2- 

 cleft, mucronate; style 2-cleft; bristles 2— 6, shorter than the obovate, mucro- 

 nate achenium. A common Eush growing in swamps, salt and fresh, and in the . 

 borders of ponds and streams, distinguished by the sharply triangular stem, and 

 rather long, channelled leaves. Ju.ly—Aug. 



* * Spikes terminal. Culms leafy. 



4. S. maritimus. Sea Cluh-rush. 



Culm acutely triangular, stout; leaves flat, linear, rough on the margin, as 

 tall as the culm ; involucre of 1 — 4 very unequal leaves ; spikes ovate orohlong, 

 several in a sessile cluster, often with 1 or more on peduncles of unequal length ; 

 glumes ovate, 3-cleft; achenium very broadly orbicular, flat on one side and 

 convex on the other, longer than the 1—6 bristles surrounding it, which some- 

 times disappear. A stout Rush of the salt marshes, growing 1—8 ft. high. The 

 spikes are of a rusty-brown color,' and vary much in size. In the stoutest plants 

 they are cylindrical, and an inch or more long. Aug. 



5. S. atrjvirens. Umhelled Cluh-rush. 



Culm obtusely triangular, rigidly erect, leafy ; loaves broad-linear rough on 

 the margin, flat; involucre of about 3 long loaves; spike ovoiil, crowded in 

 dense, globular, dark, dull-green heads, coutaining 10—20 spikes; these are ar- 

 ranged in a decompound, and mostly branching umbel of unequal divisions; 

 achenium obovate, compressed, scarcely shorter than the bristles. A common, 

 leafy species, distinguished by the globose heads of spikelets arranged in the 

 decompound umbel. Culm 2—4 ft. high. July. 



* * * Bristles capillary^ twisting, niuchlonger than the o-chenium, at length 

 projecting from the rusty-brown scales. 



6. S. lineatus. 



Bog-Rush. 



Culm triangular, very leafy ; leaves linear, flat, rough on the margin ; spikes 

 oblong, at length cylindrical, solitary, nodding, on filiiorm pedicels, arranged in 

 terminal and axillary, paniculately -branching panicles ; upper panicle with an 

 involucre much shorter than itself; bristles 6, scarcely longer than the acute 

 scales, A coarse, grassy species, common in wet meadows, 2 — Sfc high, July. 



7. S. Eriophorum. Wool-grass. 



Culm obscurely 3-angled, very leafy ; leaves narrow-linear, long, rough on 

 the margin ; leaves of the involucre longer than the decompound, paniculate 

 umbel, which is composed of ovate, clustered or pedicellate spikes ; bristles 6, 

 at length much longer than the obtuse scales, rust-colored, A coarse species 

 like the last, but distinguished at sight by its erect panicle or umbel. It varies 

 in the length of the branches of the umbel, and in some other respects. Culm 

 2—5 ft. high. Jaly—Aug. 



5. eei6phorum. 

 Spikes many-flowered. Scales imbricated all round without 

 order. Perianth consisting of numerous, rarely 6, woolly, per- 

 sistent bristles, much longer than the glumes. Stamens mostly 3. 

 Style 3-cleft. 



1. E. polystachyon. Cotton Grass. 



Culm rigidly erect, obscurely 3-angled; leaves linear, flat, terminating in a 

 triangular point; involucre 2 — 3-leaved ; spikes about 10, on slender, nodding, 

 rough or smooth peduncles. "Wool straight, nearly an inch long, A very con- 

 spicuous and common inhabitant of bogs and meadows. Culm 1—2 ft high. 



2. E. gracilis. 



Slender Cotton Grass. 



Culm slender, leafy, somewhat 3-angled, rough on the angles, with concave 

 sides ; involucre short, usually 1-leaved ; spikes 2 — 7, small, nodding, on short, 

 roughish peduncles ; wool white, m^uch longer than the flower. A not uncom- 

 mon species in bogs and swamps, distinguished from the last by its narrow, tri- 

 angular leaves. Culm 1—2 ft. high. July — Aiig. 



3. E. Virginicum, Brown Cotton Grass. 



Culm rather stout, rigid, nearly terete, leafy ; leaves long, fiat, narrowly- 

 linear, rough on the margin; involucre 2 — 4-leaved; spikes nearly sessile, erect, 

 crowded in a dense head ; wool dense, of a rusty-brown color, 3 or 4 times as 

 long as the scale; stamen 1. A common species, sufficiently distinguished by 

 the short, reddish wool. Culm 2— S ft. high. July~Aug. 



