Part 182 (1/2)

[+][+] _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 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 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 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, Ma.s.s. to Fla.

17. E. tricostata, Torr. _Culms flattish_ (1--2 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 high), from very small creeping rhizomes, _2-edged_; spikelet ovate-oblong, acute; scales ovate-oblong, obtuse, scarious, pale purple; achene pyriform, s.h.i.+ning, _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.

-- 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 sh.o.r.es, across the continent.

(Eu., Asia.)

20. E. pygmae'a, 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 s.h.i.+ning, 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. pauciflra, 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. DICHRMENA, 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 d??, _double_, and ???a, _color_).

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

2. D. latiflia, 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 ?????, _naked_, and ?a??a, _nut_.)

1. P. scirpodes, 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._