508 CYPERACE^. (sedge FAMILY.) 



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

 mon rachis : perennials, with creeping tuber-bearing rootstocks : Jiowers mostly 

 abortive. 



12. C. repens, Ell. Umbel mostly simple, erect, S-G-rajed, shorter than 

 the 3 - 5-leaved involucre ; spikelets linear, spreading, 1 2 - 24-flowered, the 

 lower ones often clustered ; scales 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°- lj° high, acute-angled, longer than the erect smooth 

 leaves. Rays 2' -4' long. Spikelets 6" - 8" long. Whole plant yellowish. 



13. C. lutescens, Torn &, Hook. Umbel simple, large, 5-7-rayed, short- 

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

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

 rounded on the back, slightly spreading at maturity ; nut obovate-ftblong ; culms 

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

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

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



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

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

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

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

 slender, 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. Rays slender, 2'-4'long. Spikelets ^'-1' 

 long. 



2. Sparsiflori. Umbel compound : spiJcelets compressed, many-flowered, scattered 

 in loose spikes at the filiform summit of the rays: scales thin, b-nen-ed, separate ; 

 joints of the rachis slightly margined: stamens 2. 



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

 volucre ; spikelets erect-spreading, oblong-linear, 1 2 - 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; style very short ; culms (1° high) slender, acute-angled, longer than 

 the smooth narrow leaves. — Santee Canal, South Carolina, Ravenel. Probabl\ 

 introduced from Eastern Asia. 



3. Palmati. Umbel compound or decompound, diffuse: spikelets 2-ranked, com- 

 pressed, many-flowered, 3-10 in a cluster at the summit of the general, and par. 

 tial rays : scales closely imbricated, 3 - 7-nerved, decurrent on the rachis : sta 

 mens 3. 



* Culms terete, knotted, leafless : involucre very short : nut oblong. 



16. C. artieulatUS, L Umbel compound, many-rayed, spreading or re. 

 curved; involucre of three bract-like pungent leaves; spikelets long (^^'-1^' 

 long), linear, spreading, 30 - 40-flowered ; scales whitish, oblong, obtuse, 7-nerveA 



