Chapter C: FUSCUS, L. Of similar habit; spikelets much smaller (2--4'' long),

the thin brown scales (greenish only on the keel) barely acutish and very faintly nerved.--Revere Beach, Mass. (_Young_); on ballast at Philadelphia. (Adv. from Eu.)

[+][+] _Perennial, propagating from hard clustered corms or bulb-like tubers._

10. C. Schweinitzii, Torr. _Culm rough on the angles (1--2 deg. high)_; umbel 4--8-rayed, rays very unequal, erect; _spikelets loosely or somewhat remotely 6--12-flowered, with convex many-nerved scales_; joints narrowly winged.--Dry sandy shores and ridges, western N. Y. and Penn. to Minn. and Kan.

11. C. filiculmis, Vahl. Culm slender, wiry, often reclined (8--15' high); _leaves linear_ (1/2--2'' wide) or filiform; _spikelets numerous and clustered in one sessile dense head, or in 1--7 additional looser heads on spreading rays_ of an irregular umbel; _joints of the axis naked; scales blunt_, greenish.--Dry sterile soil; common, especially southward.

12. C. Grayii, Torr. Culm thread-form, wiry (6--12' high); _leaves almost bristle-shaped_, channelled; _umbel simple, 4--6-rayed; spikes 5--10 in a loose head, spreading; joints of the axis winged; scales rather obtuse_, greenish-chestnut-color.--Barren sands, Plymouth, Mass., to N. J., near the coast.

Sec. 3. PAPYRUS. _Style 3-cleft; achene triangular; stamens 3; spikelets many-flowered, flattened, the carinate scales decurrent upon the rhachis as scarious wings; spikes in simple or compound umbels._

[*] _Wings of the rhachis soon separating to the base as a pair of free scales; annual._

13. C. erythrorhizos, Muhl. (Pl. 1, fig. 5--8.) Culm obtusely triangular (3'--3 deg. high); umbel many-rayed; involucre 4--5-leaved, very long; involucels bristle-form; spikelets very numerous, crowded in oblong or cylindrical nearly sessile heads or spikes, spreading horizontally, linear, flattish (3--6'' long), bright chestnut-colored; scales lanceolate, mucronulate.--Alluvial banks, L. I. to Penn., Mich., Minn., and southward; also adventive in N. Eng.

[*][*] _Wings of the rhachis persistently attached; perennial by slender running rootstocks._

[+] _Achene round-obovate; scales mucronate or acute, free or spreading._

14. C. Haspan, L. Culms sharply angled (1--11/2 deg. high); leaves linear, often reduced to membranous sheaths; _umbel spreading, the filiform rays mostly longer than the 2-leaved involucre_; spikelets narrowly linear; scales light reddish-brown, oblong, _mucronate, 3-nerved_.--Ponds and ditches, Va. to Fla. and Tex.

15. C. dentatus, Torr. (Pl. 1, fig. 9.) Culms slender (1 deg. high); leaves rigid and keeled; _umbel erect, shorter than the 3--4-leaved involucre_; scales reddish-brown, _with green keel_, ovate, _acute, 7-nerved_.--Sandy swamps, N. Eng. and northern N. Y. to S. C. and W. Va. Spikes often abortive and changed into leafy tufts.

[+][+] _Achene linear to oblong; scales appressed, pointless or nearly so._

[++] _Perennial by tuberiferous stolons._

16. C. rotundus, L. (NUT-GRASS.) Culm slender (1/2--11/2 deg. high), longer than the leaves; umbel simple or slightly compound, about equalling the involucre; the few rays each bearing 4--9 _dark chestnut-purple_ 12--40-flowered _acute spikelets_ (4--9'' long); _scales ovate, closely appressed, nerveless_ except on the keel.--Sandy fields, Va. to Fla. and Tex.; also adventive near Philadelphia and New York city. (Eu.)

17. C. esculentus, L. Culm (1--21/2 deg. high) equalling the leaves; umbel often compound, 4--7-rayed, much shorter than the long involucre; _spikelets numerous, light chestnut or straw-color, acutish_, 12--30-flowered (4--7'' long); _scales ovate or ovate-oblong narrowly scarious-margined, nerved_, the acutish _tips rather loose_; achene oblong-obovate. (C. phymatodes, _Muhl._)--Low grounds, along rivers, etc., N. Brunswick to Fla., west to Minn, and Tex.; spreading extensively by its small nut-like tubers and becoming a pest in cultivated grounds.

[++][++] _Perennial, propagating by corm-like tubers from the base; spikelets narrow, acuminate, often teretish; scales oblong-lanceolate; achene linear-oblong._

18. C. strigosus, L. Culm mostly stout (1--3 deg. high); most of the rays of the umbel elongated (1--5'), their sheaths 2-bristled; _spikelets 5--25-flowered_, spreading; scales several-nerved, much longer than the achene.--Damp or fertile soil, Canada to Fla., west to Minn., Tex., and the Pacific. Very variable in the number and length of the rays of the simple or compound umbel, and in the size of the spikelets (21/2--6 or even 12'' long), more or less densely crowded on the axis.

Sec. 4. DICLIDIUM. _Style 3-cleft; spikelets narrow, terete or nearly so, few--many-flowered, the scales closely appressed and the broad wings of the jointed rhachis enclosing the triangular achene._

19. C. speciosus, Vahl. Culm stout, _mostly low_ (5--20' high); _rays of the simple or compound umbel mostly all short and crowded; spikelets 10--20-flowered, yellowish-brown_ at maturity (3--7'' long), the short joints of its axis winged with very broad scaly margins which embrace the _ovate triangular achene; the scales ovate, obtusish, imbricately overlapping_. (C. Michauxianus, _Gray_, Manual; not _Schultes_.)--Low grounds and sandy banks, N. Eng. to Fla., west to Minn. and Tex.

20. C. Engelmanni, Steud. Resembles n. 19; but the _spikelets more slender_ and terete, _somewhat remotely 5--15-flowered_, the zigzag joints of the axis slender and narrowly winged, and the oblong or oval broadly scarious _scales proportionally shorter_, so as to expose a part of the axis of each joint, _the successive scales not reaching the base of the one above_ on the same side; achene oblong-linear, very small.--Low grounds, Mass. to Wisc. and southward.

Sec. 5. MARISCUS. _Spikelets 1--4-flowered, subterete, usually in dense heads; scales oppressed, several-nerved, the lower empty and often persistent after the fall of the rest of the spikelet; joints of the rhachis winged, enclosing the triangular achene. Perennial._

[*] _Spikelets slender and acuminate, more or less refracted in usually close umbelled spikes.--Connecting with Sec. 4._

21. C. Lancastriensis, Porter. Culm (1--2 deg. high) triangular; _leaves rather broadly linear_; umbel of 6--9 mostly elongated rays; _spikelets very numerous in short-oblong close heads_, soon reflexed, of 3--6 narrow scales, the upper and lower empty, twice the length of the linear-oblong achene, which is nearly 1'' long.--Rich soil, Penn. and N. J. to Ala.

22. C. retrofractus, Torr. Culm and leaves usually minutely downy and rough on the obtusish angles (1--3 deg. high); umbel many-rayed; _spikelets slender-awl-shaped_, very numerous in obovate or oblong heads terminating the elongated rays, _soon strongly reflexed, 1--2-flowered_ in the middle (3--5'' long); scales usually 4 or 5, the two lowest ovate and empty, the fertile lanceolate and pointed, the uppermost involute-awl-shaped; achene linear, 11/4'' long.--Sandy fields, N. J. to Fla. and Tex.

23. C. refractus, Engelm. Culm 1--2 deg. high; rays usually more or less elongated; spikelets very slender, in rather loose heads, divaricate or more or less reflexed, 2--4-flowered; achene linear, 11/4'' long.--N. J. to N. C. and Mo.

[*][*] _Spikelets very short, blunt, in densely compacted globose or cylindrical heads._

24. C. ovularis, Torr. Culm sharply triangular (6'--2 deg. high); umbel 1--6-rayed; _spikelets_ (50--100) in a _globular head, 3-flowered, oblong, blunt_ (11/2--2'' long); scales ovate, obtuse, a little longer than the ovate-oblong achene.--Sandy dry soil, southern N. Y. to Fla., west to Ill., Ark., and Tex.--Var. ROBUSTUS, Boeckl., is a form with large heads (4--8'' long), the spikelets 3--4-flowered. (C. Wolfii, _Wood_.)--Ill. to Ark., and southward.

25. C. Torreyi, Britton. Like the last, but the _heads cylindrical or oblong, spikelets usually 2-flowered_, and _achene linear-oblong_.--L. Island to Fla., west to Tex.

2. KYLLINGA, Rottboell. (Pl. 1.)

Spikelets of 3 or 4 two-ranked scales, 1--1{1/2}-flowered; the 2 lower scales minute and empty, as in Cyperus, Sec. 4, but style oftener 2-cleft and achene lenticular; spikes densely aggregated in solitary or triple sessile heads.--Culms leafy at base; involucre 3-leaved. (Named after _Peter Kylling_, a Danish botanist of the 17th century.)

1. K. pumila, Michx. Annual; culms 2--9' high; head globular or 3-lobed, whitish-green (about 4'' broad), spikelets strictly 1-flowered; upper scales ovate, pointed, rough on the keel; stamens and styles 2; leaves linear.--Low grounds, Ohio to Ill., south to Fla. and Tex. Aug.

3. DULICHIUM, Pers. (Pl. 1.)

Spikelets many- (6--10-) flowered, linear, flattened, sessile in 2 ranks on axillary solitary peduncles emerging from the sheaths of the leaves; scales 2-ranked, lanceolate, decurrent, forming flat wing-like margins on the joint below. Perianth of 6--9 downwardly barbed bristles. Stamens 3. Style 2-cleft above. Achene flattened, linear-oblong, beaked with the long persistent style.--A perennial herb, with a terete simple hollow culm (1--2 deg. high), jointed and leafy to the summit; leaves short and flat, linear, 3-ranked. (An alteration of _Dulcichinum_, an old name for a species of Cyperus.)

1. D. spathaceum, Pers.--Borders of ponds, N. Scotia to Fla., west to Minn. and Tex. July--Sept.

4. ELEOCHARIS, R. Br. SPIKE-RUSH. (Pl. 3.)

Spikelet single, terminating the naked culm, many--several-flowered. Scales imbricated all round in many (rarely in 2 or 3) ranks. Perianth of 3--12 (commonly 6) bristles, usually rough or barbed downward, rarely obsolete. Stamens 2--3. Style 2--3-cleft, its bulbous base persistent as a tubercle jointed upon the apex of the lenticular or triangular achene.--Leafless, chiefly perennial, with tufted culms sheathed at the base, from matted or creeping root-stocks; flowering in summer. (Name from [Greek: e(/los], _a marsh_, and [Greek: chai/ro] _to delight in_; being marsh plants.)

Sec. 1. _Spikelet terete, hardly if at all thicker than the spongy-cellular culm; scales firmly persistent; style mostly 3-cleft; bristles 6 (rarely 7), firm or rigid, mostly barbed downward, equalling or surpassing the triangular or lenticular achene._

[*] _Spikelet linear or lanceolate-awl-shaped, few-flowered; scales (only 3--9) few-ranked, convolute-clasping the long flattened joints of the axis, lanceolate, herbaceous (green) and several-nerved on the back, and with thin scarious margins._

1. E. Robbinsii, Oakes. _Flower-bearing culms exactly triangular_, rather stout, erect (8'--2 deg. high), also producing tufts of capillary abortive stems or fine leaves, which float in the water; sheath obliquely truncate; spikelet 4--10'' long; achene oblong-obovate, triangular, minutely reticulated, about half the length of the bristles, tipped with a flattened awl-shaped tubercle.--Shallow water, N. Eng. to Fla.

[*][*] _Spikelet cylindrical, many-flowered, 1--2' long; scales in several ranks, firm-coriaceous with scarious margin, pale, nerveless or faintly striate; culms large and stout (2--4 deg. high); basal sheaths often leaf-bearing._

2. E. equisetoides, Torr. _Culm terete, knotted as if jointed by many cross-partitions; achene smooth_ (the minute reticulation transversely linear-rectangular), with a conical-beaked tubercle.--Shallow water, R. I. to Fla., west to Mich. and Tex.

3. E. quadrangulata, R. Br. (Pl. 3, fig. 6--9.) _Culm continuous and sharply 4-angled; achene finely reticulated_, with a conical flattened distinct tubercle.--Shallow water, central N. Y. to Mich., and southward; rare.

Sec. 2. _Spikelet terete and turgid-ovate, much thicker than the very slender culm; scales thin-coriaceous or firm-membranaceous, persistent, ovate; style 3-cleft; bristles stout, barbed downward (or sometimes upward), as long as the striate and pitted-reticulated triangular achene and its tubercle; culms tufted from fibrous roots, 1--2 deg. high._

4. E. tuberculosa, R. Br. (Pl. 3, fig. 10.) _Culms flattish_, striate; spikelet 3--6'' long, many-flowered; _tubercle flattish-cap-shaped, as large as the body of the achene_.--Wet sandy soil, from Mass. along the coast to Fla.

5. E. tortilis, Schult. _Culms sharply triangular, capillary_, twisting when dry; spikelet 2--3'' long, few-flowered; _conical-beaked tubercle much smaller than the achene_. (E. simplex, _Torr._)--Eastern shore of Md. to Fla.

Sec. 3. _Spikelets terete, much thicker than the culm, many-flowered; scales imbricated in many or more than 3 ranks, thin-membranaceous or scarious, with a thicker midrib, usually brownish or purplish, sometimes deciduous._

[*] _Style 2-cleft (often 3-cleft in n. 7 and 10) and the smooth achene lenticular; culms slender or thread-form, terete or compressed._

[+] _Annuals; culms tufted, from fibrous roots._

6. E. capitata, R. Br. Culms terete, 1/4--8' high or more; _spikelets ovate to oblong_ (1--3'' long), obtuse, 15--40-flowered; _scales thickish_, round-ovate, _obtuse_, brown or brownish with green keel and paler margins; stamens 2; achene obovate, _black, about equalling the 6--8 bristles_, tipped with a flattened or saucer-shaped tubercle. (E. dispar, _E. J. Hill_.)--In sand or gravel near sloughs, Md. (_Canby_) to Fla. and Tex.; N. Ind. (_Hill_). (S. Am., etc.)

7. E. ovata, R. Br. Culms nearly terete, 8--14' high; _spikelet globose-ovoid to ovate-oblong, obtuse_, 1--6'' long (dull brown); _scales very obtuse, densely crowded in many ranks; style_ 3- (rarely 2-) _cleft_; achene obovate with narrow base, pale-brownish, shining, shorter than the 6--8 bristles, _broader than the short-deltoid, acute and flattened tubercle_. (E. obtusa, _Schult._)--Muddy places, N. Brunswick to Minn., south and westward. Variable as to the length of its bristles. A low form, with smaller and more narrowly obovate achenes, and the bristles very short or none, is E. diandra, _Wright_. A dwarf form occurs with very small and few-flowered heads. (Eu.)

8. E. Engelmanni, Steud. Like the last; spikelets usually narrowly cylindrical and acute or acutish, 2--8'' long; achene broad and truncate, the tubercle covering the summit; bristles not exceeding the achene. (E. obtusa, var. detonsa, _Gray_.)--Mass. to Penn. and Mo.

[+][+] _Perennials, with running rootstocks._

9. E. olivacea, Torr. (Pl. 2, fig. 1--5.) Culms flattish, grooved, diffusely tufted on slender matted rootstocks (2--4' high); _spikelet ovate, acutish, 20--30-flowered; scales ovate, obtuse_, rather loosely imbricated (purple with a green midrib and slightly scarious margins); achene obovate, dull, abruptly beaked with a narrow tubercle, shorter than the _6--8 bristles_.--Wet, sandy soil, Mass. to N. C., and western N. Y.

10. E. palsutris, R. Br. Culms nearly terete, striate, 1--5 deg. high; _spikelet oblong-lanceolate, pointed, many-flowered; scales ovate-oblong_, loosely imbricated, reddish-brown with a broad and translucent whitish margin and a greenish keel, the upper acutish, the lowest rounded and often enlarged; achene rather narrowly obovate, somewhat shining, crowned with a short ovate or ovate-triangular flattened tubercle, shorter than the _usually 4 bristles_.--Very common, either in water, when it is pretty stout and tall, or in wet grassy grounds, when it is slender and lower. (Eu., Asia.)--Var. GLAUCESCENS, Gray. Culms slender or filiform; tubercle narrower, acute, beak-like, sometimes half as long as the achene. With the type.--Var. CALVA, Gray. Bristles none; tubercle short, but narrower than in the type.--Var. VIGENS, L. H. Bailey. Culms very stout, rigid; achene more broadly obovoid. Lake Champlain and along the Great Lakes to Minn.

[*][*] _Achene triangular or turgid; style 3-cleft._

[+] _Bristles at least equalling the smooth achene, downwardly barbed, persistent._

11. E. rostellata, Torr. _Culms flattened and striate-grooved_, wiry, erect (1--21/2 deg. high), _the sterile ones reclining, rooting and proliferous_ from the apex (1--2 deg. high), the sheath transversely truncate; _spikelet spindle-shaped_, 12--20-flowered; scales ovate, obtuse (light-brown); achene obovate-triangular, narrowed into the confluent pyramidal tubercle, which is overtopped by the 4--6 bristles.--Marshes, N. Eng. to S. C., west to Mich. and Ky.

12. E. intermedia, Schultes. _Culms capillary, wiry_, striate-grooved, densely tufted from fibrous roots, _diffusely spreading or reclining_ (6--12' long); _spikelet oblong-ovate, acutish, loosely 10--20-flowered_ (2--3'' long); scales oblong, obtuse, green-keeled, the sides purplish-brown; achene obovoid with a narrowed base, beaked with a slender conical-awl-shaped distinct tubercle, which nearly equals the 6 bristles.--Wet slopes, Penn. to Iowa, north to Canada.

13. E. Torreyana, Boeckl. Like the preceding, but more capillary and heads smaller (11/2--2'' long), _sometimes proliferous_, the one or more short new culms from the axil of its lowest scale, which persists as an herbaceous bract; achene very much smaller, with sharper angles and a short conical tubercle, which is hardly equalled by the 3--6 slender bristles. (E. microcarpa, var. filiculmis, _Torr._)--Wet pine-barrens, N. J. to Fla.

(Addendum) 13^a. E. albida, Torr. Like n. 12 and 13 in habit, somewhat stouter; spikelet dense, ellipsoidal or oblong, 1--4'' long, acutish, with pale obtuse scales; achene very small, triangular-obovate, very smooth, with a broadly triangular tubercle upon a narrow base, shorter than or exceeding the reddish bristles.--Salt marshes, Northampton Co., Va. (_Canby_), and south to Fla. and Tex.

[+][+] _Bristles 2--4, shorter than the achene, slender and fragile, or none._

14. E. tenuis, Schultes. _Culms almost capillary, erect_ from running rootstocks, _4-angular_ and flattish (1 deg. high), the sides concave; _spikelet elliptical, acutish, 20--30-flowered_ (3'' long); _scales ovate, obtuse_, chestnut-purple with a broad scarious margin and green keel; _achene obovate, roughish-wrinkled, crowned with a small depressed tubercle_, persistent after the fall of the scales; bristles 1/2 as long as the achene or none.--N. Scotia to N. C., Minn., and Mo. June.

15. E. compressa, Sullivant. _Culms flat_, striate, tufted, erect (1--2 deg. high); _spikelet ovate-oblong_, or at length lanceolate, _20--30-flowered_ (4--7'' long); _scales lanceolate-ovate, acute_, dark purple with broad white pellucid margins and summit; _achene_ yellowish, _obovate-pear-shaped_, obtusely triangular, _wrinkled, crowned with a small conical_ and pointed _tubercle; bristles 1--4, very slender_, fragile, shorter than or equalling the achene (sometimes none or a single rudiment).--Wet places, N. Y. and Ont. to Minn. and Mo.

16. E. melanocarpa, Torr. _Culms flattened_, grooved, wiry, erect (9--18' high); _spikelet cylindrical-ovoid or oblong, thick_, obtuse, densely many-flowered (3--6'' long); scales closely many-ranked, roundish-ovate, very obtuse, brownish with broad scarious margins; _achene smooth, obovate-top-shaped, obtusely triangular, the broad summit entirely covered like a lid by the flat depressed tubercle_, which is raised in the centre into a short abrupt triangular point; bristles often obsolete; achene soon blackish.--Wet sand, Mass. to Fla.

17. E. tricostata, Torr. _Culms flattish_ (1--2 deg. high); _spikelet soon cylindrical_, densely many-flowered (6--9'' long), thickish; scales ovate, very obtuse, rusty brown, with broad scarious margins; _achene obovate, with 3 prominent thickened angles, minutely rough-wrinkled, crowned with a short-conical acute tubercle_; bristles none.--N. J. to Fla.

18. E. Wolfii, Gray. Culms slender (1 deg. high), from very small creeping rhizomes, _2-edged_; spikelet ovate-oblong, acute; scales ovate-oblong, obtuse, scarious, pale purple; achene pyriform, shining, _with 9 nearly equidistant obtuse ribs and transverse wrinkles between them; tubercle depressed, truncate_, more or less apiculate; bristles not seen.--Wet prairies, N. Iowa and S. Minn.

Sec. 4. _Spikelet more or less flattened, thicker than the slender or capillary culm, few--many-flowered; the thin membranaceous scales somewhat 2--3-ranked; style 3-cleft; bristles of the perianth 3--6, fragile or fugacious. Small or delicate species, differing from the last division chiefly in the flattish spikelets._

[*] _Tubercle contracted at its junction with the achene._

19. E. acicularis, R. Br. Culms finely capillary (2--8' long), _more or less 4-angular_; spikelet 3--9-flowered; scales ovate-oblong, rather obtuse (greenish with purple sides); achene obovate-oblong, _with 3-ribbed angles and 2--3 times as many smaller intermediate ribs_, also transversely striate, longer than the 3--4 very fugacious bristles; _tubercle conical-triangular_.--Muddy shores, across the continent. (Eu., Asia.)

20. E. pygmaea, Torr. Culms bristle like, flattened and grooved (1--2' high); spikelet ovate, 3--8-flowered; scales ovate (greenish), the upper rather acute; _achene ovoid, acutely triangular, smooth and shining, tipped with a minute tubercle_; bristles mostly longer than the fruit, sometimes wanting.--Brackish marshes, from N. Brunswick to Fla.

[*][*] _Tubercle continuous with the nutlet and not contracted at base._

21. E. pauciflora, Link. Culms striate-angled, very slender (3--9' high), scarcely tufted, on slender running rootstocks, with a short truncate sheath at base; scales of the ovate spikelet evidently 2-ranked, chestnut-brown, pointless, all flower-bearing, the two lower larger; bristles 3--6, about as long as the conspicuously beaked triangular achene. (Scirpus pauciflorus, _Lightfoot_.)--Wet places, N. Y. to N. Ill. and Minn., north and westward. (Eu., Asia.)

5. DICHROMENA, Richard. (Pl. 4.)

Spikelets aggregated in a terminal leafy-involucrate head, more or less compressed, few-flowered, all but 3 or 4 of the flowers usually imperfect or abortive. Scales imbricated somewhat in 2 ranks, more or less conduplicate or boat-shaped, keeled, white or whitish. Stamens 3. Style 2-cleft. Perianth, bristles, etc., none. Achene lenticular, wrinkled transversely, crowned with the persistent and broad tubercled base of the style.--Culms leafy, from creeping perennial rootstocks; the leaves of the involucre mostly white at the base (whence the name, from [Greek: di/s], _double_, and [Greek: chro~ma], _color_).

1. D. leucocephala, Michx. Culm triangular (1--2 deg. high); leaves narrow; those of the involucre 4--7; achene truncate, not margined.--Damp pine-barrens, N. J. to Fla. Aug., Sept.

2. D. latifolia, Baldwin. (Pl. 4, fig. 1--5.) Culm stouter, nearly terete; leaves broadly linear, those of the involucre 8 or 9, tapering from base to apex; achene round-obovate, faintly wrinkled, the tubercle decurrent on its edges.--Low pine-barrens, Va. to Fla.

6. PSILOCARYA, Torr. BALD-RUSH. (Pl. 4.)

Spikelets ovoid, terete, the numerous scales all alike and regularly imbricated, each with a perfect flower. Perianth (bristles) wholly wanting. Stamens mostly 2. Style 2-cleft, its base or the greater part of it enlarging and hardening to form the beak of the lenticular or tumid more or less wrinkled achene.--Annuals, with leafy culms, the spikelets in terminal and axillary cymes. (Name from [Greek: psilo/s], _naked_, and [Greek: kary/a], _nut_.)

1. P. scirpoides, Torr. Annual (4--10' high), leafy; leaves flat; spikelets 20--30-flowered; scales oblong-ovate, acute, chestnut-colored; achene somewhat margined, beaked with a sword-shaped almost wholly persistent style. (Rhynchospora scirpoides, _Gray_.)--Inundated places, S. N. Eng.

7. FIMBRISTYLIS, Vahl. (Pl. 3.)

Spikelets several--many-flowered, terete; scales all floriferous, regularly imbricated in several ranks. Perianth (bristles, etc.) none. Stamens 1--3. Style 2--3-cleft, often with a dilated or tumid base, which is deciduous (except in n. 4) from the apex of the naked lenticular or triangular achene. Otherwise as in Scirpus.--Culms leafy at base. Spikelets in our species umbelled, and the involucre 2--3-leaved. (Name compounded of _fimbria_, a fringe, and _stylus_, style, which is fringed with hairs in the genuine species.)

[*] _Style 2-cleft, flattened and ciliate; achene lenticular; tubercle soon deciduous; spikelets many-flowered._

1. F. spadicea, Vahl, var. castanea, Gray. Culms (1--2{1/2} deg. high) tufted from a _perennial root, rigid_, as are the _thread-form convolute-channelled leaves_, smooth; spikelets ovate-oblong becoming cylindrical, dark chestnut-color (2'' thick); _stamens 2 or 3; achene very minutely striate and reticulated_.--Salt marshes along the coast, N. Y. and N. J. to Fla. July--Sept.--Scales lighter colored than in the tropical form.

2. F. laxa, Vahl. (Pl. 3, fig. 1--5.) Culms slender (2--12' high) from an _annual root, weak_, grooved and flattish; _leaves linear, flat, ciliate-denticulate, glaucous_, sometimes hairy; spikelets ovate, acute (3'' long); _stamen 1; achene conspicuously 6--8-ribbed on each side, and with finer cross-lines_.--Low ground, Penn. to Fla., west to Ill. and La. July--Sept.

[*][*] _Style 3-cleft and achene triangular; tubercle soon deciduous; spikelets smaller and fewer-flowered._

3. F. autumnalis, Roem. & Schult. (Pl. 3, fig. 6--9.) Annual (3--16' high), in tufts; culms flat, slender, diffuse or erect; leaves flat, acute; umbel compound; spikelets oblong, acute (1--2'' long), single or 2--3 in a cluster; scales ovate-lanceolate, mucronate; stamens 1--3.--Low grounds, Maine to Fla., west to Ill. and La.

[*][*][*] _Style 3-cleft, filiform and not ciliate; achene acutely triangular; tubercle more or less persistent._

4. F. capillaris, Gray. Low annual, densely tufted (3--9' high); culm and leaves nearly capillary, the latter short; umbel compound or panicled; spikelets (2'' long) ovoid-oblong; stamens 2; achene minutely wrinkled, very obtuse.--Sandy fields, N. Eng. to Fla., west to Minn., Tex., and the Pacific.

F. VAHLII, Link (F. congesta, _Torr._), a diminutive southern species, with long filiform leaves, sessile capitate spikelets, narrow acuminate scales, and the style 2-cleft and not ciliate, has been found in ballast-sand along the northern coast.

8. SCIRPUS, Tourn. BULRUSH or CLUB-RUSH. (Pl. 3.)

Spikelets several--many-flowered, solitary or in a terminal cluster which is subtended by a 1--several-leaved involucre (this when simple often appearing like a continuation of the culm), terete, the scales being regularly imbricated all round in many or several ranks, or rarely somewhat compressed and the fewer scales inclining to be 2-ranked. Flowers to all the scales, or to all but one or two of the lowest, all perfect. Perianth of 3--6 mostly retrorsely barbed or ciliate bristles (not elongated), or sometimes wanting. Stamens mostly 3. Style 2--3-cleft, simple, not bulbous at base, wholly deciduous, or sometimes leaving a tip or point to the lenticular or triangular achene.--Culms sheathed at base; the sheaths usually leaf-bearing. Mostly perennials; flowering in summer. (The Latin name of the Bulrush.)

[*] _Spikelets solitary, few-flowered, small, often flattish; achene triangular, smooth._

[+] _Involucre a short awl-shaped bract; culms tufted (3--12' high), filiform._

1. S. caespitosus, L. _Culms terete_, wiry, densely sheathed at base, in compact turfy tufts; the upper sheath bearing a very _short awl-shaped leaf_; spikelet ovoid, rusty-color; involucral bract a rigid-pointed scale, resembling the lowest proper scale of the spikelet and scarcely surpassing it; _bristles 6, smooth_, longer than the abruptly short-pointed achene.--Coast of Maine, alpine summits of N. Eng., swamps of northern N. Y., N. Ill., Minn., and northward; also on Roan Mt., N. C. (Eu.)

2. S. Clintonii, Gray. _Culms acutely triangular_, almost bristle-like; sheaths at the base bearing a _very slender almost bristle-shaped leaf_ shorter (usually very much shorter) than the culm; involucral bract awl-shaped, mostly shorter than the chestnut-colored ovate spikelet, which has _pointless scales_; otherwise as the next.--Rather dry plains, N. Y. June.

3. S. planifolius, Muhl. _Culms triangular, leafy_ at base; _leaves linear, flat, as long as the culm_, and like it rough-edged; involucral bract a bristle-tipped scale usually overtopping the ovate or oblong chestnut-colored spikelet, the green midrib of the _scales extended into sharp points; bristles upwardly hairy_, as long as the pointless achene.--Dry or moist ground, N. Eng. to Del., west to western N. Y. and Penn.; W. Mo. (_B. F. Bush._).

[+][+] _One-leaved involucre more conspicuous, and as if continuing the culm._

4. S. subterminalis, Torr. Aquatic; culms (1--3 deg. long, thickish-filiform) partly and the shorter filiform leaves wholly submersed, cellular; the filiform green bract 6--12'' long, much surpassing the oblong spikelet; scales somewhat pointed; bristles 6, bearded downward, rather shorter than the abruptly-pointed achene.--Slow streams and ponds, N. Eng. to N. J., west to Mich. and N. Ind.--Var. TERRESTRIS, Paine; less tall, with firmer stem and leaves, and fruiting spike more turgid. Growing chiefly emersed; Herkimer Co., N. Y.

[*][*] _Spikelets clustered (rarely only one), appearing lateral, the one-leaved involucre resembling and seeming to be a continuation of the naked culm._

[+] _Culm sharply triangular, stout, chiefly from running rootstocks; spikelets many-flowered, rusty brown, closely sessile in one cluster; sheaths at base more or less leaf-bearing._

5. S. pungens, Vahl. Running rootstocks long and stout; _culm sharply 3-angled_ throughout (1--4 deg. high) with concave sides; _leaves 1--3, elongated_ (4--10' long), keeled and channelled; spikelets 1--6, capitate, ovoid, usually long, overtopped by the pointed involucral leaf; scales ovate, sparingly ciliate, 2-cleft at the apex and awn-pointed from between the acute lobes; _anthers tipped with an awl-shaped minutely fringed appendage; style 2-cleft_ (rarely 3-cleft); bristles 2--6, shorter than the obovate plano-convex and mucronate smooth achene.--Borders of salt and fresh ponds and streams, throughout N. Am. (Eu., S. Am.)

6. S. Torreyi, Olney. Rootstocks slender if any (so that the plant is readily pulled up from the mud); _culm 3-angled_, with concave sides, rather slender (2--4 deg. high), _leafy at base; leaves 2 or 3, more than half the length of the culm_, triangular-channelled, slender; _spikelets 1--4, oblong or spindle-shaped, acute, distinct_, pale chestnut-color, long overtopped by the slender erect involucral leaf; scales ovate, smooth, entire, barely mucronate; _style 3-cleft; bristles longer than the unequally triangular-obovate very smooth long-pointed achene_.--Borders of ponds, brackish and fresh, N. Eng. to Penn., Mich., and Minn.

7. S. Olneyi, Gray. _Culm 3-wing-angled, with deeply excavated sides_, stout (2--7 deg. high), the _upper sheath bearing a short triangular leaf or none_; spikelets 6--12, closely capitate, ovoid, obtuse, overtopped by the short involucral leaf; scales orbicular, smooth, the inconspicuous mucronate point shorter than the scarious apex; _anthers with a very short and blunt minutely bearded tip; style 2-cleft_; bristles 6, scarcely equalling the narrowly obovate plano-convex and mucronate achene.--Salt marshes, S. New Eng. to Fla., west to the Pacific.

S. MUCRONATUS, L. Resembling the last, 1--3 deg. high; spikelets numerous in a dense cluster, oblong-ovate, 6--8'' long or less; scales ovate, mucronate, firm, scarcely at all scarious; _style 3-cleft_; achene smaller, broadly obovate.--In a single locality in Delaware Co., Penn.; probably introduced from S. Europe.

[+][+] _Culm triangular, tall and stout, from slender running rootstocks; spikelets many-flowered, loosely umbellate or corymbed, involucellate-bracted._

8. S. Canbyi, Gray. Culm (3--5 deg. high) 3-angled, usually sharply so above, obtusely below, the sheath at base extended into a long slender triangular and channelled leaf (2--4 deg. long); involucral leaf similar (4--8' long), continuing the culm; spikelets oblong (4--6'' long), single or sometimes proliferously 2 or 3 together, nodding on the apex of the 5--9 long filiform and flattened peduncles or rays of the dichotomous umbel-like corymb, or the central one nearly sessile; scales loosely imbricated, oblong-ovate, acute, pale, thin and scarious, with a greenish nerved back; bristles 6, firm, furnished above with spreading hairs rather than barbs, equalling the slender abrupt beak of the obovate-triangular shining achene (11/2'' long).--In a pond near Salisbury, Md.

[+][+][+] _Culm terete, very tall and stout, from a deep running rootstock, leafless or very nearly so; spikelets numerous, clustered in a one-sided compound umbel-like panicle longer than the involucral leaf; involucellate bracts small, scale-like and rusty-scarious; scales of the spikelets rusty or chestnut-brown, scarious, the midrib extended into a mucronate point._

9. S. lacustris, L. (GREAT BULRUSH.) Culm 3--9 deg. high, 1/2--1' thick at base; spikelets ovate-oblong (3--4'' long); scales mostly a little downy on the back and ciliate; style 2-cleft; achene pale and dull, obovate with a narrowed base, plano-convex, mucronate-pointed, usually overtopped by the 4--6 slender downwardly barbed bristles. (S. validus, _Vahl._)--Common everywhere in still fresh water. (Eu., Asia, etc.)

[+][+][+][+] _Culms slender from an annual root, terete, plano-convex or obtusely triangular, naked; the sheaths rarely bearing a short leaf; spikelets few or several in a sessile cluster, sometimes solitary, much overtopped by the involucral leaf; bristles often few or wanting._

10. S. debilis, Pursh. (Pl. 3, fig. 1--5.) _Culms obtusely triangular_, with somewhat hollowed sides, 1--2 deg. high, yellowish-green, shining; spikelets 3--12, capitate, ovate-oblong, obtuse (3--4'' long), chestnut-brown; involucral leaf often horizontal at maturity; scales roundish; stamens 3; style 2--3-cleft; _bristles 6, stout_, downwardly barbed, equalling or two surpassing the obovate _turgidly plano-convex_ (or bluntly 3-sided) abruptly mucronate-pointed _smoothish_ achene.--Swamps, Mass. to S. C., Minn. and Neb. Aug., Sept.

11. S. Smithii, Gray. _Culms terete_, slender, 3--12' high, often leaf-bearing from the upper sheath, dull green as are the 1--3 oblong-ovate acute spikelets; involucral leaf always erect; scales oblong-oval; style 2-cleft; _bristles 1 or 2 minute rudiments or none_; achene _somewhat lenticular, smooth_, deciduous with the scales.--Wet shores, Delaware Bay to L. Ontario, Mich., N. Ind., and Ill. July.

12. S. supinus, L., var. Hallii, Gray. _Culms filiform_, 5--12' high; upper sheath rarely distinctly leaf-bearing; spikelets 1--7 in a sessile or sometimes geminately proliferous cluster, ovate-oblong becoming cylindrical, greenish; scales ovate, strongly keeled, mucronate-pointed; stamens 2 or 3; style 2-cleft; _bristles none; achene obovate-orbicular_, mucronate, plano-convex, _strongly wrinkled transversely_.--Wet shores, Ill. to Tex.; also found in E. Mass. (_Hitchings_). (Eu.)

[*][*][*] _Spikelets in simple or mostly compound umbellate or cymose-panicled clusters, many-flowered, terete; involucre of mostly several flat leaves; culm tall, from tufted or running rootstocks, triangular, leafy, sedge-like; leaves rough on the margin; style mostly 3-cleft._

[+] _Spikelets large (6--15'' long); midrib of the scales extended beyond the mostly lacerate or two-cleft apex into a distinct awn._

13. S. maritimus, L. (SEA CLUB-RUSH.) Leaves flat, linear, as long as the stout culm (1--3 deg. high), those of the involucre 1--4, very unequal; spikelets few--several in a sessile cluster, and often also with 1--4 unequal rays bearing 1--7 ovate or oblong-cylindrical (rusty-brown) spikelets; awns of the scales soon recurved; _achene obovate-orbicular, compressed, flat on one side, convex or obtuse-angled on the other, minutely pointed, shining, shorter than the_ 1--6 unequal and deciduous (sometimes obsolete) _bristles_.--Saline localities, on the coast from N. Scotia to Fla., and in the interior across the continent. (Eu.)--Var. MACROSTACHYOS, Michx.; larger, with very thick oblong-cylindrical heads (1--1{1/2}' long), and longer involucral leaf (often 1 deg. long).

14. S. fluviatilis, Gray. (RIVER C.) Culm very stout, 3--5 deg. high; leaves flat, broadly linear (1/2' wide or more), tapering gradually to a point, the upper and those of the very long involucre very much exceeding the _compound umbel; rays 5--9, elongated, recurved-spreading_, each bearing 1--5 ovate or oblong-cylindrical acute paler heads; scales less lacerate and awns less recurved; _achene obovate, sharply and exactly triangular, conspicuously pointed, opaque_, scarcely equalling the 6 rigid bristles.--Borders of lakes and large streams, W. Vt. to Conn. and Penn., west to Minn. and Iowa.

[+][+] _Spikelets very numerous, small (1--3'' long); scales mucronate-pointed or blunt; umbel-like cymose panicle irregular, compound or decompound; culm 2--5 deg. high, unusually leafy; leaves broadly linear, green and rather soft; bristles very slender, often more or less tortuous and naked below._

15. S. sylvaticus, L. _Spikelets lead-colored, clustered 3--10 together at the end of the mostly slender ultimate divisions_ of the open decompound panicle, ovoid or lance-ovate, 2'' long; scales bluntish; bristles 6, downwardly barbed throughout, rather exceeding the triangular short-pointed achene; style 3-cleft.--Along brooks, E. Mass. to N. Y.; rare.

Var. digynus, Boeckl. Style 2-cleft and the achene not at all angled on the back; stamens 2, and bristles 4. (S. microcarpus, _Presl._)--N. Scotia and N. Eng. to Minn., and westward.

16. S. atrovirens, Muhl. Leaves somewhat more rigid; _spikelets dull greenish-brown, densely conglomerate (10--30 together) into close heads_, these also usually densely clustered in a less compound panicle; scales pointed; _bristles_ sparsely and strongly _downwardly barbed above the middle, naked below_, nearly straight, as long as the conspicuously pointed and obovate-oblong triangular achene.--Wet meadows and bogs, N. Scotia and N. Eng., west to Minn., Kan., and the Pacific.

17. S. polyphyllus, Vahl. Culm usually more leafy; _spikelets yellow-brown, ovate_, becoming cylindrical, _clustered 3--8 together in small heads on_ the short ultimate divisions of the _open decompound umbel_; scales mucronate; _bristles 6, usually twice bent, soft-barbed toward the summit only_, about twice the length of the achene.--Swamps and borders of ponds, western N. Eng to N. C., west to Minn, and Ark.

9. ERIOPHORUM, L. COTTON-GRASS. (Pl. 3.)

Bristles naked, usually very numerous, often silky and becoming greatly elongated. Otherwise as in Scirpus.--Spikelets single or clustered or umbellate, usually involucrate with erect scale-like bracts, upon a leafy or naked stem; scales membranaceous, 1--3-nerved. Style very slender and elongated, 3-cleft. Achene acutely triangular. (Name composed of [Greek: e)/rion], _wool_ or _cotton_, and [Greek: phoro/s], _bearing_.)

[*] _Bristles 6, rust-colored, becoming tortuous and entangled; culm very leafy, bearing numerous spikelets in an involucrate decompound cymose-panicled umbel._

1. E. lineatum, Benth. & Hook. Culm triangular, leafy (1--3 deg. high); leaves linear, flat, rather broad, rough on the margins; umbels terminal and sometimes axillary, loose, drooping, the terminal with a 1--3-leaved _involucre much shorter than the long slender rays_; spikelets oblong, becoming cylindrical (2--4'' long), on thread-like drooping pedicels; _bristles at maturity scarcely exceeding the_ ovate green-keeled _pointed scales_; achene sharp-pointed. (Scirpus lineatus, _Michx._)--Low grounds, western N. Eng. to Ga., west to Minn. and Mo.

2. E. cyperinum, L. (Pl. 3, fig. 6--10, under Scirpus.) (WOOL-GRASS.) Culm nearly terete (2--5 deg. high); leaves narrowly linear, long, rigid, those of the _involucre 3--5, longer than the umbel_, the rays at length drooping; spikelets exceedingly numerous, ovate, clustered, or the lateral pedicelled, woolly at maturity (11/2--3'' long); the rust-colored _bristles much longer than the pointless scales_; achene short-pointed. (Scirpus Eriophorum, _Michx._)--Wet meadows and swamps, Newf. to Fla., west to Minn. and Iowa. Exceedingly variable in the character and size of the umbel, the typical form having the spikelets mostly clustered in small heads.--Var. LAXUM has the spikelets scattered, the lateral long-pedicelled.

[*][*] _Bristles 6, crisped, white; spikelet single, small; involucre of one short bract._

3. E. alpinum, L. (Pl. 3, fig. 1--6.) Culms slender, many in a row from a running rootstock (6--10' high), scabrous, naked; sheaths at the base awl-tipped.--Cold bogs, Lab. to N. Eng., west to Minn. June. (Eu.)

[*][*][*] _Bristles very numerous, not crisped, forming dense cottony heads in fruit._

[+] _Culm bearing a single spikelet; involucre none._

4. E. vaginatum, L. Culms in close tufts (1 deg. high), leafy only at the base, above with 2 inflated leafless sheaths; root-leaves long and thread-form, triangular-channelled; scales of the ovate spikelet long-pointed, lead-color at maturity.--Cold and high peat-bogs, N. Eng. to Penn., Mich., Minn., and northward. May, June. (Eu.)

[+][+] _Culm leafy, bearing several umbellate-clustered heads, involucrate._

5. E. Virginicum, L. Culm rigid (2--4 deg. high); leaves very narrowly linear, elongated, flat; _spikelets nearly sessile, crowded in a dense cluster or head; wool rusty or copper-color_, only thrice the length of the scale; stamen 1.--Bogs and low meadows, Newf. to Fla., west to Minn. and Neb. July, Aug.--Var. ALBUM, Gray, has the wool white. N. New York.

6. E. polystachyon, L. Culm rigid (1--2 deg. high), obscurely triangular; _leaves linear, flat, or barely channelled below_, triangular at the point; _involucre 2--3-leaved_; spikelets several (4--12), on smooth nodding peduncles, some of them elongated in fruit; achene obovate; _wool white_, very straight (1' long or more).--Bogs, Newf. to Ga., Minn., and westward. June, July. (Eu.)--Var. LATIFOLIUM, Gray; peduncles rough; leaves sometimes broader and flatter.

7. E. gracile, Koch. Culm slender (1--2 deg. high), rather triangular; _leaves slender, channelled-triangular_, rough on the angles; _involucre short and scale-like, mostly 1-leaved_; peduncles rough or roughish-pubescent; spikelets 3--7, small, when mature the copious white wool 6--9'' long; achene elliptical-linear.--Cold bogs, Newf. to N. J., west to Minn. and Mo. Scales in our plant mostly light chestnut and about 3-nerved. June--Aug. (Eu.)

10. FUIRENA, Rottboell. UMBRELLA-GRASS. (Pl. 2.)

Spikelets many-flowered, terete, clustered or solitary, axillary and terminal. Scales imbricated in many ranks, awned below the apex, all floriferous. Perianth of 3 ovate or heart-shaped petaloid scales, mostly on claws, and usually with as many alternating small bristles. Stamens 3. Style 3-cleft. Achene triangular, pointed with the persistent base of the style. Culms from a perennial root, obtusely triangular. (Named for _G. Fuiren_, a Danish botanist.)

1. F. squarrosa, Michx., var. hispida, Chapm. (Pl. 2, fig. 1--7.) Stem (1--3 deg. high) leafy; leaves and sheaths usually densely hairy; spikelets ovoid-oblong (4--6'' long), clustered in heads, bristly with the spreading awns of the scales; perianth-scales rhombic or deltoid-ovate, with a short thick awn or point, the interposed mostly barbed bristles shorter than the achene.--Sandy wet places, N. J. to Fla., west to Ky. and Tex.

Var. pumila, Torr. Usually low (1--6' high or more), with 1--6 spikelets; perianth-scales narrowly to broadly oblong or ovate, long-stipitate and attenuate to a long awn; barbed bristles usually exceeding the achene.--Mass. to N. J., Fla., and La.; Mich. The commonest form.

11. HEMICARPHA, Nees. (Pl. 2.)

Spikelet, flowers, etc., as in Scirpus, except that there is a minute translucent scale (readily overlooked) between the flower and the axis of the spikelet. Stamen only one. Style 2-cleft. Bristles or other perianth none. (Name from [Greek: e(/mi], _half_, and [Greek: ka/rphos], _straw_ or _chaff_, in allusion to the single inner scalelet.)

1. H. subsquarrosa, Nees. Dwarf or minute annual (1--5' high); involucre 1-leaved, as if a continuation of the bristle-like culm, and usually with another minute leaf; spikelets 2--3 (barely 2'' long); scales brown, tipped with a short recurved point.--Sandy borders of ponds and rivers, N. Eng. to Fla., west to the Pacific.

12. LIPOCARPHA, R. Br. (Pl. 2.)

Spikelets terete, many-flowered, in a terminal close cluster involucrate by leafy bracts. Scales spatulate, regularly imbricated all round in many ranks, awnless, deciduous, a few of the lowest empty. Inner scales (bractlets) 2 to each flower, thin, one between the scale of the spikelet and the flower, one between the latter and the axis of the spikelet. Bristles or other perianth none. Stamens 1 or 2. Style 2--3-cleft. Achene flattish or triangular, naked at the tip.--Culms leafy at base. (Name formed of [Greek: li/pos], _fat_, and [Greek: ka/rphos], _chaff_, from the thickness of the inner scales of some species.)

1. L. maculata, Torr. Annual; culm (4--8' high) much longer than the linear concave leaves; spikelets (1--2'' long) green and dark-spotted; inner scales delicate; stamen one; achene oblong with a contracted base.--Springy or miry places, Va. to Fla.; near Philadelphia, probably adventive.

13. RHYNCHOSPORA, Vahl. BEAK-RUSH. (Pl. 4.)

Spikelets panicled or variously clustered, ovate, globular, or spindle-shaped, terete, or sometimes flattish; but the scales open or barely concave (not boat-shaped nor keeled); the lower commonly loosely imbricated and empty, the uppermost often subtending imperfect flowers. Perianth in the form of bristles (mostly 6). Stamens mostly 3. Achene lenticular, globular, or flat, crowned with a conspicuous tubercle or beak consisting of the persistent indurated base or even of the greater part of the style.--Chiefly perennials, with more or less triangular and leafy culms; the spikelets in terminal and axillary clusters; flowering in summer. (Name composed of [Greek: r(y/nchos], _a snout_, and [Greek: spora/], _a seed_, from the beaked achene.)

Sec. 1. RHYNCHOSPORA proper. _Spikelets terete or biconvex, few--many-flowered; style conspicuously 2-cleft, its base only forming the tubercle of the mostly lenticular achene; bristles usually present, merely rough or barbed-denticulate (not plumose)._

[*] _Achene transversely wrinkled; bristles mostly 6, upwardly denticulate._

1. R. cymosa, Nutt. _Culm triangular; leaves linear_ (1/4' wide); cymes corymbose, the _spikelets crowded and clustered; achene round-obovate_, twice the length of the bristles, four times the length of the depressed-conical tubercle.--Low grounds, Penn. and N. J. to Fla., west to N. Ind. and Ill.

2. R. Torreyana, Gray. (Pl. 4, figs. 1--5.) _Culm nearly terete, slender; leaves bristle-form_; cymes panicled, somewhat loose, the _spikelets mostly pedicelled; achene oblong-obovate_, longer than the bristles, thrice the length of the broad compressed-conical tubercle.--Swamps; pine-barrens of N. J. to S. C.

3. R. inexpansa, Vahl. _Culm triangular_, slender; _leaves narrowly linear; spikelets spindle-shaped, mostly pedicelled, in drooping panicles; achene oblong_, half the length of the slender bristles, twice the length of the triangular-subulate tubercle.--Low grounds, Va. to Ga.

[*][*] _Achene smooth and even._

[+] _Bristles 6, long and conspicuous, upwardly denticulate._

4. R. fusca, Roem. & Schultes. Culm 6--12' high; _leaves bristle-form channelled_; spikelets ovate-oblong, few, clustered in 1--3 loose heads (dark chestnut-color); _achene obovate, half the length of the bristles_, equalling the triangular-sword-shaped acute tubercle, which is rough serrulate on the margins.--Low grounds, N. Brunswick to N. J., west to L. Superior. (Eu.)

5. R. gracilenta, Gray. Culms very slender, 1--2 deg. high; _leaves narrowly linear_; spikelets ovoid, in 2--4 small clusters, the lateral long-peduncled; _achene ovoid, rather shorter than the bristles_, about the length of the flat awl-shaped tubercle.--Low grounds, southern N. Y. and N. J. to Fla.

6. R. oligantha, Gray. Culm and leaves filiform, 6--12' high; spikelets very few (1--4), ovate-oblong; bristles plumose below the middle; achene obovate-oblong, bearing a conical tubercle {1/3} its length.--Del. (_Canby_) to Fla.

[+][+] _Bristles none, or 1--3 and minute; spikelets pale, 1-flowered._

7. R. pallida, M. A. Curtis. Culm (1--2 deg. high) acutely triangular; leaves and spikelets as in the next species, but only a terminal dense cluster, which is less white or turns pale reddish-tawny; achene obovate-lenticular, tipped with a minute depressed and apiculate tubercle; the delicate bristles 4--5 times shorter or obsolete.--Bogs in pine-barrens of N. J. and N. C.

[+][+][+] _Bristles long, denticulate downward, or both ways in n. 11._

[++] _Spikelets white or whitish, becoming tawny with age, perfecting only a single flower; stamens usually 2; bristles 9--12, or even 20._

8. R. alba, Vahl. Culm slender (1--2 deg. high), triangular above; leaves narrowly linear or almost bristle-form; spikelets lanceolate, densely crowded in a head-like terminal corymb and usually one or two lateral ones; achene oblong-obovate with a narrowed base, scarcely longer than the flattened-awl-shaped tubercle, shorter than the bristles.--Bogs, Newf. to Fla., west to N. Ind., Minn., and Oregon. (Eu.)

[++][++] _Spikelets chestnut-colored or darker in_ n. _10 and 11, few--several-flowered; stamens 3; bristles usually 6._

9. R. capillacea, Torr. Culm 6--9' high, slender; _leaves bristle-form; spikelets 3--6 in a terminal cluster_, and commonly 1 or 2 on a remote axillary peduncle, _oblong-lanceolate_ (pale chestnut-color, 3'' long); _achene oblong-ovoid_, stipitate, very obscurely wrinkled, about _half the length of the_ (6, rarely 12) _stout bristles_, and twice the length of the lanceolate-beaked tubercle.--Bogs and rocky river-banks, N. Vt. to Penn., west to western N. Y. and Minn.--Var. LEVISETA, Hill. Bristles perfectly smooth. N. W. Ind.

10. R. Knieskernii, Carey. Culm 6--18 deg. high, slender; _leaves narrowly linear_, short; _spikelets numerous, crowded in 4--6 distant clusters, oblong-ovate_ (scarcely 1'' long); _achene obovate_, narrowed at base, _equalling the bristles_, twice the length of the triangular flattened tubercle.--Pine-barrens of N. J. (on bog iron ore exclusively) to Va.; rare.

11. R. glomerata, Vahl. Culm 1--3 deg. high; _leaves linear, flat; spikelets numerous in distant clusters or heads_ (often in pairs from the same sheath), _ovoid-oblong_; achene obovate, margined, narrowed at base, as long as the lance-awl-shaped flattened tubercle, which equals the always _downwardly barbed bristles_.--Low grounds, N. Eng. to Fla., west to Mich. and N. Ind.

12. R. cephalantha, Gray. Culm stout (2--3 deg. high); _leaves narrowly linear, flat, keeled; spikelets very numerous, crowded in 2 or 3 or more dense globular_ heads which are distant (and often in pairs), _oblong-lanceolate_, dark brown; achene orbicular-obovate, margined, narrowed at base, about as long as the awl-shaped beak; _bristles_ twice longer, stout, _barbed downward and sometimes also upward_.--Sandy swamps, Long Island to N. J. and Fla.

Sec. 2. CERATOSCHOENUS. _Spikelets lanceolate, acuminate, in fruit flattish, cymose-panicled, of only one perfect and 1--4 staminate flowers; scales few; bristles rigid, minutely scabrous upward; style simple or barely 2-toothed, filiform and gradually thickened downward, in fruit persistent as an exserted, slender-awl-shaped, upwardly roughened beak, several times longer than the smooth flat obovate achene; coarse perennials; spikelets in flower 4'', in fruit including the projecting beak about 1' long._

13. R. corniculata, Gray. (HORNED RUSH.) Culm 3--6 deg. high; leaves about 6'' wide; _cymes decompound, diffuse; bristles awl-shaped_, stout, unequal, _shorter than the achene._--Wet places, Penn. to Fla., west to S. Ind. and Mo.

14. R. macrostachya, Torr. (Pl. 4, fig. 1--4.) _Cymes_ decompound, or in the northern form _somewhat simple_ and smaller, and the spikelets usually more clustered; _bristles capillary, twice the length of the achene_.--Borders of ponds, Mass. to N. J. and Fla.; rare.

14. CLADIUM, P. Browne. TWIG-RUSH. (Pl. 5.)

Spikelets ovoid or oblong, of several loosely imbricated scales; the lower empty, one or two above bearing a staminate or imperfect flower; the terminal flower perfect and fertile. Perianth none. Stamens 2. Style 2--3-cleft, deciduous. Achene ovoid or globular, somewhat corky at the summit, or pointed, without any tubercle, in which it differs from Rhynchospora. (Diminutive of [Greek: kla/dos], _a branch_, from the repeatedly branched cyme of the original species.)

1. C. mariscoides, Torr. Perennial; culm obscurely triangular (1--2 deg. high); leaves narrow, channelled, scarcely rough-margined; cymes small; the spikelets clustered in heads 3--8 together on 2--4 peduncles; style 3-cleft.--Bogs, N. Scotia to Del., west to S. Minn. and Iowa. July.

15. SCLERIA, Berg. NUT-RUSH. (Pl. 5.)

Flowers monoecious; the fertile spikelets 1-flowered, usually intermixed with clusters of few-flowered staminate spikelets. Scales loosely imbricated, the lower empty. Stamens 1--3. Style 3-cleft. Achene globular, stony, bony, or enamel-like in texture. Bristles, etc., none. Perennials, with triangular leafy culms, mostly from creeping rootstocks; flowering in summer; all in low ground or swamps. Inflorescence, in our species, of terminal and axillary clusters, the lower clusters usually peduncled. (Name, [Greek: skleri/a], _hardness_, from the indurated fruit.)

[*] _Achene smooth._

1. S. triglomerata, Michx. _Culm_ (11/2--3 deg. high) _and broadly linear leaves roughish_; fascicles of spikelets few, the lowest peduncled, the upper _somewhat in threes; achene ovate-globose_ or depressed, on an obscure crustaceous disk.--Mass. and Vt. to Fla., west to Minn. and Tex.--Var. GRACILIS, Britton. Culms slender (1--2 deg. long); fascicles few-flowered, the lower (2--3-flowered) on very long filiform peduncles; achene not more than half as large, acutish.--N. J.

2. S. oligantha, Ell. Culms slender, 2 deg. high, the angles somewhat winged; _leaves linear_ (2'' wide), _smooth_ except the scabrous apex; lateral fascicles 1 or 2, usually on long exserted peduncles; _achene ovate, on a tuberculate disk_.--Va. to Fla. and Tex.

[*][*] _Achene papillose or warty._

3. S. pauciflora, Muhl. Smoothish or hairy; culm slender (9--24' high); leaves narrowly linear; fascicles few-flowered, the lateral pedunculate, sessile, or wanting; bracts ciliate; achene globose-ovate; the disk a narrow ring bearing 3 pairs of minute tubercles.--N. H. to Ohio, south to Fla. and Tex.

[*][*][*] _Achene reticulated or wrinkled._

4. S. reticularis, Michx. (Pl. 5, fig. 6--10.) Culms slender, _erect_, scabrous (1--21/2 deg. high); leaves linear (1--11/2'' wide), smooth; lateral fascicles 1--3, loose, remote, nearly erect, _on short often included peduncles_; bracts glabrous; achene globose, _regularly reticulated and pitted_, not hairy, resting upon a double greenish conspicuously 3-lobed disk, the inner appressed to and deciduous with the achene.--E. Mass. to Fla.--Var. PUBESCENS, Britton. Edges of reticulations more or less hairy, especially toward the apex; lateral fascicles generally on longer peduncles. Pine-barrens of N. J. to Fla.--Var. OBSCURA, Britton. Achene bony, its surface with very obscure reticulations, nearly smooth at the summit. R. I. and N. C.

5. S. Torreyana, Walpers. Culms weak, _diffuse_, slightly scabrous or smooth; leaves linear (2--4'' wide), smooth; lateral fascicles loose, on _more or less elongated and drooping filiform peduncles_; achene _irregularly pitted-reticulated or pitted-rugose with the ridges somewhat spirally arranged and more or less hairy_ (sometimes smooth); otherwise as in the last. (S. laxa, _Torr._)--Pine-barrens, N. J. to Fla. and Tex.

6. S. verticillata, Muhl. Smooth; culms simple, slender (4--24' high); leaves narrowly linear, _fascicles_ 3--9-flowered, 4--6, _sessile in an interrupted spikelet; achene_ globose (1/2'' broad), somewhat triangular at base, _rough-wrinkled with short elevated ridges; disk obsolete_.--E. Mass. to Ont., Minn., and south to the Gulf.

16. CAREX, Ruppius. SEDGE. (By L. H. BAILEY.)

Flowers unisexual, destitute of floral envelopes, disposed in spikes; the staminate consisting of three stamens, in the axil of a bract, or _scale_; the pistillate comprising a single pistil with a bifid or trifid style, forming in fruit a hard lenticular or triangular achene, which is enclosed in a sac (_perigynium_) formed by the complete union of the borders of a bractlet or of connate bractlets and borne in the axil of a bract, or _scale_. Staminate and pistillate flowers borne in different parts of the spike (spike _androgynous_), or in separate spikes on the same culm, or rarely the plant dioecious.--Perennial grass-like herbs with mostly triangular culms, 3-ranked leaves, usually with rough margins and keel, and spikes in the axils of leafy or scale-like bracts, often aggregated into heads. An exceedingly critical genus, the study of which should be attempted only with complete and fully mature specimens. (The classical Latin name, of obscure signification; derived by some from [Greek: kei/ro], _to cut_, on account of the sharp leaves--as the English name _Shear-grass_.) (Pl. 5 and 6.)

Synopsis of Sections and Groups.

Sec. 1. CAREX proper. Staminate flowers forming one or more terminal linear or club-shaped spikes (often pistillate at base or apex). Pistillate flowers usually in distinct and simple mostly peduncled spikes. Cross-section of perigynium circular, obtusely angled, or prominently triangular in outline. Style mostly 3-parted and achene triangular or triquetrous.

[*] 1. Physocarpae. Perigynium mostly straw-colored at maturity, papery in texture, usually more or less inflated, smooth (sometimes hairy in n. 6), nerved, tapering into a beak as long as or longer than the body; spikes few to many, distinct, compactly flowered; stigmas 3 (2 in n. 10).

[+] 1. _Pauciflorae._ Perigynium greenish, linear-lanceolate or almost needle shaped, not inflated, strongly deflexed at maturity, several times longer than the inconspicuous scale; spike androgynous, the pistillate flowers at base, few.--Sp. 1.

[+] 2. _Lupulinae._ Perigynium green or greenish tawny or sometimes yellow, more or less inflated (except in n. 2--4) long, usually very turgid at base, mostly erect or nearly so, very gradually attenuate to a long slenderly toothed beak exceeding the scale; spikes 3 or more, the staminate mostly 1 and stalked, the pistillate often sessile, usually short and thick, often becoming dark colored in drying.--Sp. 2--8.

[+] 3. _Vesicariae._ Perigynium smooth and shining, much inflated, at maturity straw-colored or sometimes purple, beaked and conspicuously short toothed (entire in n. 10), usually prominently few nerved, much shorter than in [+] 2; staminate spikes commonly 2 or more; pistillate spikes as a rule long and densely cylindrical.--Sp. 9--16.

[+] 4. _Pseudocyperae._ Perigynium less inflated, more conspicuously nerved or even costate, and with more or less setaceous or awned teeth; scale usually awned; spikes mostly nodding or spreading, comose in appearance, greenish, greenish-yellow, or ochroleucous.--Sp. 17--19.

[+] 5. _Squarrosae._ Perigynium obconic or obovoid, squarrose in exceedingly dense short spikes.--Sp. 20, 21.

[*] 2. Trachychlaenae. Perigynium mostly thick and hard in texture, often scabrous or hirsute, straight-beaked; pistillate spikes compactly flowered, mostly large, erect or nearly so; staminate spikes 1 or more; stigmas 3. Generally large and coarse.

[+] 1. _Shortianae._ Terminal spike androgynous, staminate below; perigynium small, scabrous, nearly beakless, entire.--Sp. 22.

[+] 2. _Anomalae._ Terminal spike all staminate; pistillate spikes long and cylindrical, mostly dense; perigynium broad and short, short-beaked, the orifice very slightly notched or entire, mostly granulate.--Sp. 23.

[+] 3. _Hirtae._ A heterogeneous group, distinguished from [+] 2 by the longer and more deeply cut beak (slightly toothed in n. 24), and by the hairy perigynium (smooth in n. 25)--Sp. 24--27.

[+] 4. _Paludosae._ Staminate spikes 2 or more, long stalked; the pistillate 2--several, usually all peduncled, long and heavy, loose-flowered, erect or nodding; perigynium large, thick in texture, strongly nerved, mostly smooth, usually conspicuously beaked. Coarse species.--Sp. 28, 29.

[*] 3. Microrhynchae. Parallel with [*] 2; distinguished in general by the much smaller and nearly or entirely beakless and mostly entire-mouthed perigynium, which is much thinner in texture; stigmas 2 or 3. Paludose and alpine species, of various habit, mostly with colored spikes, often in dense tufts or tussocks.

[+] 1. _Atratae._ Terminal spike club-shaped and androgynous with the staminate flowers below (very rarely all staminate in n. 32); pistillate spikes mostly short and dark-colored, erect or drooping; stigmas 3.--Sp. 30--32.

[+] 2. _Rigidae._ Mostly stiff, with short erect closely flowered spikes, an entirely staminate terminal spike, dark colored scales, and bracts with purple or black auricles at base; stigmas 2 or 3.--Sp. 33.

[+] 3. _Acutae._ Mostly larger and more slender, usually paludose, with green or light-colored large and long spikes; stigmas 2 (3 in n. 39). Distinguished from [+] 2 mainly by habit.--Sp. 34--39.

[+] 4. _Cryptocarpae._ Large, with nodding or drooping large spikes, their dark scales very long and conspicuous; stigmas 2.--Sp. 40, 41.

[+] 5. _Pendulinae._ Distinguished from [+] 4 by the smaller size, smaller spikes, sheathless bracts, and whitish, more or less granulated, nearly pointless perigynium; stigmas 3.--Sp. 42--45.

[*] 4. Hymenochlaenae. Perigynium mostly light green or whitish, usually thin and membranous, often somewhat inflated or loosely investing the achene, commonly smooth and shining (hairy in n. 46, sometimes in n. 47), slender or oblong, attenuate to a distinct or long minutely toothed straight beak (or beakless or nearly so in [+] 1 and n. 55); pistillate spikes several or many, mostly loosely flowered and on filiform nodding or widely spreading peduncles; bracts leaf-like; terminal spike staminate or androgynous; stigmas 3. Mostly rather tall and slender upland species.

[+] 1. _Virescentes._ Terminal spike pistillate at top; pistillate spikes oblong or cylindrical, dense, erect; perigynium ovate or obovate, nearly or quite beakless, often hairy.--Sp. 46, 47.

[+] 2. _Sylvaticae._ Terminal spike all staminate; pistillate spikes mostly long-exserted, slender; perigynium few-nerved, contracted into a cylindrical beak which is longer than the body.--Sp. 48.

[+] 3. _Flexiles._ Terminal spike all staminate; pistillate spikes rather thick (very small in n. 50), more or less drooping; perigynium beaked, few-nerved or nerveless, tawny or whitish.--Sp. 49, 50.

[+] 4. _Debiles._ Terminal spike all staminate (occasionally pistillate above in n. 53); pistillate spikes very narrow and slender, long-exserted and nodding, mostly very loosely flowered; perigynium rather small, not turgid, prominently beaked.--Sp. 51--53.

[+] 5. _Gracillimae._ Terminal spike pistillate at top; pistillate spikes habitually thicker than in [+] 4; perigynium ovate-oblong, more or less turgid; the beak short or none.--Sp. 54--57.

[+] 6. _Griseae._ Terminal spike staminate; perigynium more or less turgid or plump, often glaucous, scarcely beaked, finely striate; spikes erect.--Sp. 58, 59.

[*] 5. Spirostachyae. Perigynium smooth or minutely granulated or rarely somewhat serrate on the margins, prominently nerved, mostly yellowish, squarrose, mostly beaked (entirely beakless in n. 63), the orifice entire; staminate spike mostly single; pistillate spikes 2--5, short (usually 1' long or less), yellow or fuscous, compactly flowered; stigmas 3.--Medium-sized species, growing in meadows and grassy swales.

[+] 1. _Granulares._ Spikes scattered, cylindrical, the lowest long-stalked; bracts erect, long and leafy; sheaths short or nearly obsolete.--Sp. 60, 61.

[+] 2. _Extensae._ Spikes mostly approximate or aggregated at the top of the culm (becoming remote in C. extensa), the lowest 1 or 2 subtended by a long and leafy mostly abruptly spreading and nearly or entirely sheathless bract. Terminal spike sometimes androgynous.--Sp. 62.

[+] 3. _Pallescentes._ Spikes globular or short-oblong, obtuse, sessile or short-peduncled, approximate at the top of the culm; bracts short, leaf-like, sheathless; perigynium entire at the orifice, the beak none or very short and stout.--Sp. 63, 64.

[*] 6. Dactylostachyae. Perigynium mostly short and triangular, mostly with a short and straight or curved beak, green or greenish, scarcely inflated; scales of the pistillate spikes mostly whitish (sometimes dark-colored in the _Digitatae_), often small; staminate spike mostly one; pistillate spikes short (seldom exceeding 1'), commonly rather loosely flowered and slender (spike single and plant dioecious in n. 83); bracts sheathing, the sheaths often conspicuous and colored.--Low and lax or slender species inhabiting meadows and copses.

[+] 1. _Oligocarpae._ Slender and narrow-leaved, with leafy bracts and inconspicuous green sheaths; perigynium rounded on the angles, finely many-striate, often somewhat punctulate as in n. 58, to which the group forms a transition.--Sp. 65--67.

[+] 2. _Laxiflorae._ Slender and more or less broad-leaved, with mostly leafy bracts, green or purple sheaths, and loosely flowered spikes; perigynium mostly conspicuously three-angled, with a more or less curved beak.--Sp. 68--74.

[+] 3. _Paniceae._ Mostly stouter and narrow-leaved, with thinner spikes; perigynium often strongly nerved, not conspicuously triangular, often somewhat turgid; bracts and sheaths various.--Sp. 75--78.

[+] 4. _Bicolores._ Small species with a beakless, more or less round or pyriform perigynium, which is commonly glaucous; terminal spike androgynous or all staminate; stigmas mostly 2.--Sp. 79.

[+] 5. _Digitatae._ Low species; sheaths membranaceous or hyaline and colored, either not prolonged into a bract or the bract very short and not foliaceous; perigynium more or less three-angled, often hairy, the beak straight or nearly so.--Sp. 80--83.

[*] 7. Sphaeridiophorae. Perigynium mostly short and rounded, three-angled in the _Triquetrae_, firm or hard in texture, not inflated, hairy or scabrous, the beak straight and usually bifid; staminate spike one; pistillate spikes short (1' long or less), usually globular or short-oblong, more or less sessile and approximate or the longer ones radical (spike single in n. 84); bracts sheathless, short, or obsolete; stigmas rarely two.--Low species of dry ground, with leaves all radical.

[+] 1. _Scirpinae._ Spike one, unisexual; plant dioecious.--Sp. 84.

[+] 2. _Montanae._ Spikes two to several, the lowest occasionally long-peduncled and radical; perigynium rounded, contracted above and below, mostly bearing two prominent ribs, more or less hairy.--Low species of dry soils.--Sp. 85--91.

[+] 3. _Triquetrae._ Taller; spikes mostly approximate at the top of the culm, oblong or cylindrical; perigynium conspicuously 3-angled.--Sp. 92.

[*] 8. Phyllostachyae. Perigynium much as in the _Montanae_; spike one, staminate above; pistillate flowers few, often remote, usually on a more or less zigzag rhachis; scales prolonged and leaf-like.--Sp. 93--95.

[*] 9. Leptocephalae. Perigynium thin in texture, green, oblong or lanceolate or linear in general outline, beakless; spike one, staminate above, thin and slender; stigmas mostly three.--Small, slender and grass-like.--Sp. 96.

[*] 10. Physocephalae. Spike one, globular or short-oblong, staminate at the apex; perigynium straw-colored, paper-like, more or less inflated; stigmas three. Leaves remarkably broad in our species.--Sp. 97.

Sec. 2. VIGNEA. Staminate flowers few and inconspicuous, borne at the base or apex of the pistillate spikes. Pistillate flowers in short sessile spikes (or spike single in some cases), which are commonly more or less aggregated into heads or even panicled. Perigynium plano-convex. Styles two and achene lenticular.--The spikes, especially the uppermost, usually have contracted bases when the staminate flowers are borne below the pistillate ones, and empty scales at the top when the staminate flowers are borne at the summit.

[*] 11. Acroarrhenae. Staminate flowers borne at the top of the spikes (or, in the _Multiflorae_ and _Arenariae_, spikes often wholly staminate and the plants occasionally dioecious).

[+] 1. _Foetidae._ Spikes tawny or brown, not elongated, very densely aggregated into a continuous globose somewhat chaffy head; perigynium ovate or ovate-lanceolate, nerveless or nearly so, mostly thin in texture.--Sp. 98, 99.

[+] 2. _Vulpinae._ Spikes mostly yellow or tawny when mature, densely aggregated or sometimes somewhat scattered below or even panicled; perigynium thick in texture, spongy at base, mostly stipitate, bearing very conspicuous nerves, which converge below and are especially prominent on the outer side.--Sp. 100--102.

[+] 3. _Multiflorae._ Heads various, mostly loosely flowered, sometimes a panicle, yellow or tawny; spikes short (rarely longer than broad), staminate flowers sometimes occupying whole spikes in the middle or at the apex of the head; perigynium mostly small and short and nearly nerveless, or in some species becoming nearly lanceolate and more or less prominently nerved, firm in texture, usually numerous.--Sp. 103--108.

[+] 4. _Arenariae._ Spikes longer than in the last section, linear or nearly so, aggregated into short, almost globose heads; perigynium lanceolate or ovate-lanceolate, mostly larger and more delicate in texture; scales awn-pointed or very acute. Staminate flowers variously situated.--(C. arenaria.)

[+] 5. _Muhlenbergianae._ Spikes green or nearly so when mature, aggregated or scattered, never in compound heads; perigynium mostly short-ovate, staminate flowers always at the top of the spike.--Sp. 109--114.

[+] 6. _Dioicae._ Spike commonly one, small; plants small and slender, often dioecious.--Sp. 115--117.

[*] 12. Hyparrhenae. Staminate flowers borne at the base of the spikes (or in n. 124 and 125 variously situated).

[+] 1. _Elongatae._ Spikes silvery green or sometimes tawny when mature, distinct, mostly small; perigynium not wing-margined nor conspicuously broadened, mostly nearly flat on the inner surface.--Sp. 118--124.

[+] 2. _Ovales._ Spikes tawny or dark, rather large, sometimes crowded; perigynium with a more or less thin or winged margin, which is mostly incurved at maturity, rendering the perigynium concave inside.--Sp. 125--132.

[+] 3. _Cyperoideae._ Spikes green, oblong, densely crowded into a short head subtended by two or three leafy bracts which are erect and prolonged from six inches to a foot; perigynium linear-lanceolate, scarcely margined.--Sp. 133.

Artificial Key.

Spike 1, staminate at top; scales of pistillate flowers leaf-like
Sp. 93-95

Spike 1, scales not leaf-like.

Usually dioecious, stigma 2 115-117

Stigmas 3.--

Perigynium densely hairy 84

Spike staminate at base; perigynia squarrose 21

Spike staminate at top.--

Globose; leaves broad 97

Perigynium nearly linear, beakless 96

Perigynium long, spindle-shaped 1

Spikes several or numerous, sessile, spicate or capitate; stigmas 2.

All in a globose or ovoid uninterrupted head.

All staminate above.--

Usually green at maturity 112, 114

Usually yellow or tawny or brown 98, 99, 104, 105

All staminate below.--

Leafy-bracteate 133

Not leafy-bracteate.--

Green 118-120

Usually tawny or brown 125-132

Some or all of the spikes distinct or the head interrupted.

Staminate and pistillate flowers variously disposed, some of the
spikes often unisexual.

Head large and long 108, C. arenaria

Head short or linear 124, 125

Spikes staminate above 100-114

Spikes staminate below 118-133

Spikes usually more or less pedicelled, the wholly or partially
staminate spikes uppermost.

Terminal spike (rarely the 2 or 3 uppermost) staminate only at base.

Stigmas 2 34-38, 79

Stigmas 3; spikes erect,

Short and squarrose 20, 21

Not squarrose 22, 30, 32, 46, 47, 54, 79

Stigmas 3; spikes more or less drooping 31, 51-53, 55-57

Terminal spike or spikes staminate.

Stigmas 2.--

Spikes spreading or pendulous 34, 37, 40, 41

Spikes erect or nearly so 9-16, 34-41, 85-91, 79

Stigmas 3; spikes spreading or drooping.

Perigynium prominently 3-angled 68-74

Perigynium large, thin, much inflated 9-16

Perigynium firmer, not inflated.

Beakless 42-45

Beaked or prominently pointed.--

Teeth long, stiff and sharp 17-19

Teeth short and thin, or none 30, 31, 39, 48-53

Stigmas 3; spikes erect or ascending.

Perigynium hairy.--

Spikes very large, globose 6

Spikes very small, sessile or nearly so 81-83, 85-92

Spikes cylindrical, heavy 24-28

Perigynium granular-roughened 23

Perigynium smooth,

Thin and turgid, loosely enclosing the achene.--

Beakless 58, 59

Beaked 5-17

Firm in texture, not inflated,

Long-beaked, deeply toothed 2-4, 26, 28

Less prominently beaked, short-toothed, sharply 3-angled
69-74

Wholly beakless and pointless 58, 59, 63, 78, 79

Very small, black and shining; leaves capillary 80

Culm and leaves thinly pubescent 64

Perigynium more or less pointed or beaked.

Spikes spreading or drooping 51-53, 68-70, 75

Spikes erect 60-62, 65-68, 71-78

[*] 1. PHYSOCARPAE.--[+] 1. _Pauciflorae_.

1. C. pauciflora, Lightf. (Pl. 5, fig. 1--16.) Very slender but erect, 6--18' high; leaves very narrow, much shorter than the culm; staminate and pistillate flowers 2--5; perigynium at maturity easily detached.--Cold sphagnum swamps, New Eng. to N. Penn. and Minn.; local. (Eu.)

[*] 1.--[+] 2. _Lupulinae_.

[++] _Teeth of the perigynium strongly reflexed._

2. C. subulata, Michx. Green, very slender but erect, 6'--2 deg. high; leaves narrow, somewhat shorter than the culm; bracts leafy, sheathing; pistillate spikes 2--4, scattered, 2--6-flowered; perigynium deflexed.--Deep sphagnum swamps, R. I. to E. Penn., and southward; very local.

[++][++] _Teeth erect or spreading._

[=] _Whole plant yellowish; perigynium little or not at all inflated._

3. C. Michauxiana, Boeckl. Slender but stiff and erect, 1--2 deg. high; leaves narrow and firm, shorter than the culm; spikes 2--3, the lowest usually remote and short-peduncled, the remainder aggregated and sessile; staminate spike small, wholly sessile; perigynium not inflated, erect or spreading, twice longer than the blunt scale. (C. rostrata, _Michx._)--Bogs and lake-borders, mountains of N. H. and N. Y., and westward to L. Superior; local.

4. C. folliculata, L. Stout, 2--3 deg. high; leaves very broad and flat, lax; pistillate spikes 3--4, scattered, all but the uppermost prominently peduncled; staminate spike short-peduncled; perigynium larger, inflated, the scale awned and nearly as long.--Cold swamps, New Eng. to N. J. and Penn., and west to Mich.; rather local.

[=][=] _Plant green; perigynium much inflated._

5. C. intumescens, Rudge. Slender, 18--30' high; leaves narrow, pistillate spikes two, loosely 1--8-flowered, the perigynium erect-spreading, not prominently many-nerved.--Wet pastures and swamps; common.

6. C. Grayii, Carey. Larger and stouter; leaves broad and flat, 3--4'' wide; pistillate spikes 1 or 2, the lowest often peduncled, perfectly globular and compactly 12--30-flowered, the perigynium spreading or deflexed and prominently many-nerved.--Meadows and copses, Vt. to Ill., and south to Ga.; rare eastward.--In var. HISPIDULA, Gray, the perigynium is sparsely hispidulous.

7. C. lupulina, Muhl. Very stout and leafy; leaves rather broad and loose; pistillate spikes 2--6, approximate at the top of the culm, all closely sessile or the lower sometimes short-peduncled, oblong or short-cylindrical, very heavy and densely flowered; staminate spike small and sessile; perigynium large and rather soft, erect or but slightly spreading, giving the spike a hop-like aspect (whence the name). (C. lurida, _Bailey_.)--Swamps and wet pastures; frequent.

Var. pedunculata, Dewey. Spikes more or less scattered, some or all prominently peduncled; staminate spike usually conspicuous, often long-peduncled, very variable in size; perigynium more spreading. (C. gigantea, _Rudge_.)--With the species, but more common.

Var. polystachya, Schwein. & Torr. Stouter, the leaves very broad (often {1/2}'); bracts broad and far exceeding the culm; pistillate spikes 4--6, all long (3--4') and cylindrical, more or less short-peduncled, somewhat scattered, becoming yellow; perigynium very large, ascending. (C. lupuliformis, _Sartw._)--N. Y. and N. J.; not common.