742 ORDER 155. CYPERACE^E. 



Ivs. flat, linear, shorter than the stem ; umbel compound, diffuse ; invol. 



2-leaved ; spikelets lanceolate, acute, somewhat 4-sided, 2 3 together ; glumes 

 brown, rnucrouate ; ach. white. "Wet places, along rivers, etc., N. Eng. ! to Ga., 

 W. to Mo. July. (Fimbristilis, R. & S.) 



2 T. coarctata. Culm filiform, teretish, 8 to 12' high; Ivs. setaceous, with bearded 

 sheaths; umbel compound, contracted; invoL Ivs. many, short setacepus, one a 

 little longer than the umbel; spikes 15 to 20, linear-oblong, 3'' long; glumes 

 about 12, acute, rust-colored ; stam. 2 ; sty. deeply 3-cleft; ach. obovate, 3-angled. 

 Dry, sandy soils, Oar. to Fla. (Isolepis Torr. Scirpus Ell.) 



3 T. capillaris. Culm caespitous, nearly naked, 3-angled, capillary, 4 8' high ; 

 Ivs. subradical, setaceous, shorter than the stem ; spikes ovoid, 2 4, in a simple 

 umbel, inner one sessile; glumes oblong, ferruginous, margin pubescent; ach. 

 white. In sandy fields, Mass, to Fla., "W. to Ky. and Ohio. Aug. (Isolepis, R. 

 & S. I. ciliatifolius, Ell, a taller form (7 to 10') with 4 to G spikes.) 



4 T. stenophylla. Culms twisted, 2 to 4' high, setaceous, as long as the seta- 

 ceous Ivs. ; spikes 4 to 6, ovoid, acute, few-flowered, sessile, in a dense head ; 

 invol. Ivs. 3 or 4, dilated at base, ciliate, 2 or 3 times longer (3 to 12") than the 

 head ; glumes ovate-acuminate, keeled, greenish ; sty. 3-cleft ; ach. short-triangu- 

 lar, black-pruinous when mature. Dry soils, Car. to Fla. Jl. Sept. (Isolepis, 

 Kunth. Scirpus, E1L) 



5 T. Warei. Culm filiform, terete, furrowed, near If high ; Ivs. 2 to 3' long, 

 channeled ; spikes 6 to 12, ovoid, in a dense head; invol. Ivs. 3 or 4, longer than 

 the head, base dilated and cut-fringed; glumes ovate, obtuse, ciliate; ach. white, 

 rugulous, obovate-triangular. W. Fla. (Ware, Torr. Gyp.). Very near the preced- 

 ing. (Isolepis, Torr.) 



6 T. carinata. Culm flattened, setaceous, 3 to 6' high, with a short, solitary 

 setaceous leaf near the base ; spike single, ovoid, lateral near the top of the culm ; 

 glumes green, 5 to 8, broad-ovate, veined acuminate ; sty. 3-cleft ; ach. short- 

 triangular, grayish, half as long as the glume. Near N. Orleans (Hale) (Isolepis, 

 Hook. & Arn.). 



12. PSYLOCAR'YA, Torr. (Gr. o/uAof, naked, ttapva, nut; no 

 bristles.) Flowers . Glumes GO, imbricated all round, all fertile ; 

 perigynium ; stam. 2 ; filaments long, persistent ; style 2-cleft, dilated 

 or tuberculate at base ; achenium biconvex, crowned with the persis- 

 tent style. Stems leafy. Spikes lateral and terminal, cymous. 



1 P. scirpoides Torr. Culm slender, leafy, smooth, 3-sided, 5 9' high ; Ivs. 

 linear, smooth, 3 5' by 1", cauline about 2 ; cymes terminal, and one from the 

 sheath of each cauline leaf; spikes about 3" long, oblong-ovate, in small, loose 

 dusters, 20 30 ' -flowered ; glumes chestnut-colored, thin ovate, acute; ach. tumid, 

 dark brown, crowned with the long style, which is much dilated at base.: Bor- 

 ders of ponds, Smithfield, R. I. (Olney), Mass. (Greene), and Ark. (Hale). 



2 P. rhyncospproides Torr. Culm 8 to 14' high, leafy, smooth; Ivs. linear, 2" 

 broad, overtopping the culm; umbel few-rayed ; spikes ovoid, 2 to 3" long, all pe- 

 dunculate, 8 to IQ-flowered ; glumes roundish ovate, obtuse, pale brown; ach. 

 roundish, lenticular, strongly rugous; tubercle short, obtuse,. Quincy, Fla. 

 (Chapman). 



13. DICHROM'ENA, Richard. (Gr. d^, two, xp&(J<a, color.) Spikes 

 flattened, collected into a terminal head ; glumes imbricate on all sides, 

 many abortive ; perigynium none ; stamens 3 ; styles 2-cleft ; achenium 

 lens-shaped, crowned with the broad, tuberculate* base of the style. 

 Rhizome creeping. Culms leafy. Lvs. of the invol. usually whitened 

 at the base. 



1 D. leucocephala MX. -Culm triangular, 2 to 3f high; Ivs. concave, narrow, 

 shorter than the culm; invol. 6 to 8-leaved, the Ivs. lanceolate, long-pointed, 

 whitened below, spreading, 1 to 4' long ; ach. truncate at the summit, transversely 

 rugulous. Bogs, Md. to Fla, and La. Known at a distance by its white in- 

 volucre. 



