50G CYPERACK.E. (SKDOE FAMILY.) 



higli ; leaves and 3-leavcd involucre narrowly linear. (C. fascieulatus, Ell.'>) — 

 Low grounds, Florida, and northward. July and Aug. 



2. C. rivularis, Kunth. Umbel of 3 - 4 rays, one or two of them longer 

 than the spikelets ; spikelets 3-6 iu a cluster, oblong-linear, acute, many-flow- 

 ered ; scales pale straw-color, ovate, obtuse, appressed ; rachis margined ; sta- 

 mens 2 ; nut round-obovate, transversely roughened, black and shining ; culms 

 6'- 12' high, slender; leaves and 3-leaved involucre linear. — Marshy banks of 

 streams, Georgia, Florida, and westward. Aug. 



3. C. diandrus, Torr. Umbel of 2-5 short and unequal rays, the longer 

 ones longer than the spikelets ; spikelets lanceolate-oblong, acute, brownish or 

 dark brown, spreading ; scales ovate, obtuse, appressed, green on the keel ; 

 rachis margined ; stamens 2 ; nut oblong-obovate, roughish, dull gray. — Wet 

 places, North Carolina, and northward. Aug. — Culms 4'- 10' high. Invo- 

 lucre 3-lcaved. This and the preceding arc probably only diandrous forms of 



No. 1. 



* * Spikelets scattered on the common rachis {spiked). 



4. C. Nuttallii, Torr. Umbel sessile or of 3-6 rays, l'-2' long; spike- 

 lets numerous on the rays, spreading, linear-lanceolate, acute, light or yellowish 

 brown, 12-20-flowered, the lower ojies commonly compound; scales rigid, ob- 

 long-ovate, acute or mucronate, appressed ; stamens 2 ; nut oblong-obovate, 

 very obtuse, grayish and minutely pitted; culms clustered, 3-angled, 4' -15' 

 high ; leaves and involucre narrowly linear. (C. flavescens. Ell. C. holosericcus, 

 Link.?) — Salt or brackish soil, Florida, and northward. July -Sept. — Plant 

 commonly yellowish and glossy throughout. Sjjikelets rarely crowded in a 

 terminal head. 



5. C. flavicomus, Michx. Umbel compound, many-rayed ; sjiikelcts very 

 numerous, crowded, linear, acute, 1 2 - 30-flowercd ; scales loosely imbricated, yel- 

 lowish, round-obovate, cmarginatc, with broad and scarious margins, at length 

 spreading ; rachis broadly margined ; stamens 3 ; nut obovate, black, smooth 

 and shining, barely shorter than the scale; culms thick, obtuse-angled, l°-3° 

 high ; leaves broadly linear, glaucous beneath, as long as the culm. — Low 

 grounds and ditches, Georgia and South Carolina. May -Sept — Involucre 

 3 - 5-leaved. Spikelets 6" - 9" long. 



6. C. microdontus, Torr. Umbel of 4 - 8 rays, simple or somewhat 

 cpmpound ; spikelets numerous, crowded, linear, acute, 15 - 25-flowered, pale 

 brown; scales thin, ovate, acute, closely imbricated; rachis .slightly margined ; 

 stamens 2 ; nut linear-oblong or somewhat club-shaped, short-pointed, grayish 

 and minutely pitt(d; culms filiform. 3-anglcd, 6' - 12' high ; leaves and elon- 

 gated involucre very narrow. — Margins of ponds and streams, Florida to North 

 Carolina. July - Sept. — Rays 1'- 2' long. Spikelets 4" - 7" long. 



^ 2. CYPERUS Proi'KR. Stifle S-cle/l : nnt 3-angled: joints of the rachis 

 winfifd liy the adnute decittrent scal>s, rarely wingless. 



1. SricATi. (Jiiibd simple or compound: spikelets few - many- flowered, distinct, 

 spreadinp, furuiinii loo^r or compact sj)ikes at the summit of the rays : scales rigid, 

 7 - ll-ncrv(d : joints of the rachis commonly conspicuously wimjid : stamens 3. 



