CYPERACEjfc. (SEDGE FAMILY.) 521 



acute-angled nut. Muddy banks of the Chipola 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 entanyled. (Trichophornm.) 



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 cyperinum, 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-GRASS. 



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. 

 Nut 3-angled or lenticular. Perennials, with leafy culms, in our species, and 

 clustered or umbelled spikes. 



1. E. 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' long. 



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. P. spadicea, Vahl. Perennial; culms clustered, nearly terete, rigid 

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

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

 44* 



