CYPERACEiE. (sedge FAMILY.) 577 



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



Spikelets aggregated in a termiual leafy-involucrate head, more or less com- 

 pressed, few-flowered, all but 3 or 4 of the flowers usually imperfect or abor- 

 tive. Scales imbricated somewhat in 2 ranks, more or less couduplicate 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 creep- 

 ing perennial rootstocks ; the leaves of the involucre mostly white at tlie base 

 (wlience the name, from Sis, double, and xp^l^^y color). 



1. D. leucocephala, Michx. Culm triangular (1-2° bigh) ; 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. (PI. 4, tig. 1-5.) Culm stouter, nearly te- 

 rete ; 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. (PI. 4.) 



Spikelets ovoid, terete, the numerous scales all alike and regularly imbri- 

 cated, each with a perfect flower. Periantli (bristles) wholly wanting. Sta- 

 mens 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 termiual and axillary 

 cymes. (Name from ^^iKos, naked, and Kapva, nut.) 



1. P. scirpoides, Torr. Annual (4- 10' high), leafy ; leaves flat; spike- 

 lets 20 - 30-flowered ; scales oblong-ovate, acute, chestnut-colored ; achene 

 somewhat margined, beaked with a sword-shaped almost wholly persistent 

 style. (Rhynchospora scirpoides, Graij.) — Inundated places, S. N, Eng. 



7. FIMBRISTYLIS, Vahl. (PI. 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 Avith a dilated or tumid base, which is deciduous (except 

 in n. 4) from the apex of the naked lenticular or triangular achene. Other- 

 wise as in Scirpus. — Culms leafy at base. Spikelets in our species umbelled, 

 and the involucre 2-3-leaved. (Name compounded oijimhria, a fringe, and 

 stfjlus, style, which is fringed with hairs in the genuine species.) 



nc- Style 2-cleft, flattened and cHiaie; achene lenticular ; tubercle soon deciduous ; 



spikelets many -flowered. 



1 F. spadicea, Vahl, var. eastanea, Gray. Culms (l-2|o high) 

 tnited honm perennial 7'oot, rigid, a.s 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 reticidated. 

 — Salt marshes along the coast, N, Y. and N. J. to Fla. July - Sept. — Scales 

 lighter colored than in tlie tropical form. 



2. P. laxa, Vahl. (PI. 3, fig. 1 - .5.) Culms slender (2-12' high) from 

 an annual root, veak, grooved and flattish: leaves linear,flat, ciliate-deniiculnfe, 



