506 CYPERACER. (SEDGE FAMILY.) 
high ; leaves and 3-leaved involucre narrowly linear. (C. fasciculatus, EU. 2) — 
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 in 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-leaved. This and the preceding are 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, 1/-2! long; spike- 
lets numerous on the rays, spreading, linear-lanceolate, acute, light or yellowish 
brown, 12 —20-flowered, the lower ones 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 eaves and involucre narrowly linear. (C. flavescens, Zi. C. holosericeus, 
Link.?) — Salt or brackish soil, Florida, and. northward. July -Sept. — Plant 
commonly yellowish and glossy throughout. Spikelets rarely crowded in a 
terminal head. 
5. C. flavicomus, Michx. Umbel compound, many-rayed ; spikelets very 
numerous, crowded, linear, acute, 19 — 30-flowered ; scales loosely imbricated, y el- 
lowish, round-obovate, emarginate, 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, 19 - 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" Jong. 
6. C. microdontus, Torr  Umbel of 4-8 rays, simple or somewhat 
compound; spikelets numerous, crowded, linear, acute, 15 - 25-flowered, pale. 
brown; scales thin, ovate, acute, closely imbricated ; rachis slightly margined 5 
stamens 2; nut linear-oblong or somewhat club-shaped, short-pointed, gray 
and minutely pitted; culms filiform, 3-angled, 6' — 12' high; leaves and eoe 
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 Prorer. Style 3-cleft: nut 3-angled: joints of the rachis 
- winged by the adnate decurrent scales, rarely wingless. 
1. SercATI. Tatal 
“spreading, fors 
se or compact spikes at the summit of the rays + sea 
P x S. soni -flower ed, distinct, | 
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