508 CYPERACEJE. (sedge family.) 



* * Spikelets compressed, somewhat 2-ranked, mostly Jew and scattered on the com- 

 mon i-achis : perennials, with creeping tuber-bearing rootstocks : Jiowers mosth/ 

 ubortice. 



12. C. repens, Ell. Umbel mostly simple, erect, 5- 6-raycd, shorter than 

 the 8— 5-leaved involucre; spikeleta linear, spreading, 12- 24-flowered, the 



lower ones often clustered ; Bcales oblong, obtuse or short mucronate, com- 

 pressed-keeled, thin-margined, spreading at the apex, yellowish brown ; nut ob- 

 long, triquetrous, acute. — Sandy soil near the coast, Florida, and northward. 

 July - Sept. — Culms 1°- H° high, acute-angled, longer than the erect smooth 

 leaves. Kays 2' -4' long. Spikelcts 6" - 8" long. Whole plant yellowish. 



IS. C. lutescens, Torr. & Hook. Umbel simple, large, 5 - 7-ravcd, short- 

 er than the 3 -5-leaved involucre; spikelcts horizontal, flat, linear, 30 - 40-flow- 

 ered, the lowest 2-3 in a cluster; scales light brown, oblong-lanceolate, acute, 

 rounded on the hack, slightly spreading at maturity; nut obovate-oblong ; culms 

 stout (2° -3° high), acute-angled, shorter than the broadly linear leaves. — Key 

 West. Nov. — Leaves 3" -6" wide, very smooth. Rays 4' - 8' long. Spike- 

 lets 1' long, 1 \" wide, serrate, the lower ones with a bristly involuccl. 



14. C. rotundus, L. Umbel simple or compound, 3-8-raycd, mostly 

 longer than the 3-leavcd involucre; spikes composed of 3-9 scattered linear 

 flat 20 - 30-flowered spikelcts; scales oblong, obtuse, appressed, 7-nerved on the 

 green keel, the membranaceous sides dark chestnut; nut obovatc ; culms smooth, 

 Blender, longer than the broadly linear crowded spreading rough leaves. (C. 

 Hydra, Michx.) — Sandy soil, along the coast, Florida to North Carolina. Aug. 

 and Sept.— Culm 9' -18' high. Kays slender, 2' -4' long. Spikelcts J'-l' 

 long. 



2. Sparsifi.ort. Umbel compound : spih lets compressed, many-flowered, scattered 

 in loose s]>ikes at the filiform summit of the rays: scales thin, 5-nerved, separate • 

 joints of the rachis slightly margined: stamens 2. 



15. C. Iria, L. Umbel 6 - 8-rayed, erect, shorter than the 3 - 4-leaved in- 

 volucre; spikelcts erect-spreading, oblong-linear, 12- 24-flowered ; scales spread- 

 ing, nearly orbicular, obtuse or emarginate, short-mucronate, 5-nerved on the 

 green keel, the thin whitish sides minutely pitted ; nut oblong-obovate, abruptly 

 pointed; Btyle very short; culms (1° high) slender, acute-angled, longer than 

 the smooth narrow leaves. — Santec Canal, South Carolina, Ravenel, Probabl} 

 introduced from Eastern Asia. 



.!. 1'm.mati. Umbel compound or decompound, diffuse: spikeleta 2-ranked, com- 

 pressed, many-flowered, 8 — 10 In a cluster al th< summit qj the general and par, 

 tin! my*: smbs closely imbricated, 8 — 7-nerved, decurrent on the rachis: sta 

 mens .'!. 



* Culms terete, I notU </, /< afl* ss « involucre vt ry slant .■ nut oblong. 



16. C. articulatus, L Umbel compound, many raved, spreading <n- re 

 curved; involucre of three bract like pungent leaves; Bpikeleta long (l'-l$ r 

 long), linear, spreading, 30 - M)-flowered ; scales whitish, oblong, obtuse, 7-nerved 



