CYPERACE^. (sedge FAMILY.) 521 



acate-angled nut. — Muddy banks of the Cliipola River, and of Flat Creek, near 

 Aspalaga, Florida, to South Carolina; not common. Aug. — Culm 2° -4° 

 high, often proliferous at the joints. Umbel 6'- 12' long. Spikes 2"-3" long. 



* * Bristles 6, capillary, smooth, crisped and entangled. (Tiichophorum.) 



10. S. Eriophorum, Michx. Culm nearly terete, with the joints remote ; 

 leaves linear, elongated, keeled; umbel terminal, decompound, spreading or 

 recurved, shorter than the 3 - 5-leaved involucre ; spikes single or clustered, 

 ovate ; scales thin, lanceolate, obtuse ; bristles many times longer than the 

 oblong compressed-3-angled beak-pointed nut, at length exserted, and covering 

 the spike with woolly down. (Trichophorum cyperinura, Pers.) — Swamps and 

 low grounds, Florida, and northward. July - Sept. — Culm 2° - 4° high. 



11. S. lineatus, Michx. Culm 3-angled; leaves flat, linear-lanceolate; 

 umbels lateral and terminal, longer than the 1 - 3-leaved involucre ; spikes all 

 single, cylindrical ; scales rigid, keeled, mucronate ; bristles barely exserted ; nut 

 as in the preceding. Swamps, Georgia, and northward. June - Aug. — Culm 

 2° - 3° high. Spikelets 3" - 4" long. 



9. ERIOPHORUM, L. Cotton-Gkass. 



Spikes many-flowered. Scales imbricated in many rows. Perianth composed 

 of numerous (rarely 6) smooth and flat hairs, much longer than the scale, and 

 forming a woolly or silky tuft. Stamens commonly 3. Style 3-cleft, deciduous. 

 NutSangled or lenticular. — Perennials, with leafy culms, in our species, and 

 clustered or umbelled spikes. 



1. B. Virginicum, L. Culm nearly terete, rigid; leaves narrowly linear, 

 elongated ; spikes densely clustered, nearly sessile, erect ; involucre 2 - 3-leaved ; 

 wool reddish, thrice the length of the brownish scales ; nut compressed-3-angled, 

 acute. — Bogs and swamps, Florida, and northward. June -Aug. — Culm 2°- 

 3° high. Leaves 10'- 18' Idng. 



2. E. polystachyon, L. Culm terete ; leaves broadly linear, 3-angled 

 at the summit ; spikes umbelled, distinct, on slender at length nodding peduncles ; 

 involucre 2-leaved, shorter than the umbel ; wool white, many times longer than 

 the dark brown scales ; nut obtuse. — Meadows and bogs in the upper districts, 

 Georgia, and northward. Aug. and Sept. — Culm 1° - 2' high. Leaves 3' - 6' 

 long. 



10. PIMBRISTYLIS, Vahl. 



Spikes many-flowered. Scales imbricated in several rows. Perianth none, 

 Stamens 1-3. Style 2-cleft, commonly flat and fringed on the margins, tumid 

 at the base, deciduous. Nut lenticular. . — Culms jointless, leafy at the base. 

 Involucre 1 - several-leaved. Spikes terminal, umbellate or clustered. 



* Spikes umbelled, 

 1. F. spadicea, Vahl. Perennial ; culms clustered, nearly terete, rigid 

 (2° - 3° high) ; leaves long, linear or flliform, concave, rough on the margins ; 

 umbel simple or compound, erect ; involucre 2 - 3-Ieaved ; spikes ovate or ob- 

 44* 



