the tip; anthers usually to about 4 mm. long; bristles numerous, white or nearly 

 so; achenes blackish, 2-3 mm. long, broadly oblanceolate to obovate, 2 to 3 times 

 as long as wide. E. angustifolium Honck. 



In wet bogs, cold swamps and marshes, in N. M. (Taos Co.), Apr.-Aug.; Nfld. 

 to Ore. and N.M. 



4. Fuirena Rottb. Umbrella-grass 



Perennials, usually rhizomatous, the lowest leaves often with reduced blades, 

 the upper 1, 2 or 3 leaves functioning as bracts with each subtending a very much 

 condensed often glomerulelike inflorescence of 1 to 10 spikelets; spikelets globose 

 to oblong-cylindric; scales numerous, spirally imbricate, usually pubescent, all 

 fertile, usually obovate and awn-tipped (awn short in one species); perianth of 3 

 stalked scalelike or paddlelike structures often thickened at maturity, often addi- 

 tionally three perianth bristles alternating with these stalked structures; style 

 branches 3; achene plumply trigonous, shiny, apically tapering into a more or 

 less persistent indurate linear style base often nearly as long as the achenial body 

 itself. 



The genus is related to, and should be included within, Scirpus, according to 

 some authors. A small genus of 40 species in warmer regions of the world. 



1. All or nearly all blades reduced; awns of spikelet scales only about 1 mm. long, 

 ascending 1. F. scirpoidea. 



1. Nearly all blades well-developed, only the lowest reduced; awns of spikelet 



scales usually 2-4 mm. long, often spreading apically (2) 



2(1 ). Each of the 3 prominent perianth parts with an acuminate apex which often 

 arches toward the style 2. F. squarrosa. 



2. Each of the 3 prominent perianth parts with an acute, blunt or even emarginate 



apex and often subapically on the dorsal side with a mucro or a 

 minute awn 3. F. simplex. 



1. Fuirena scirpoidea Michx. Fig. 185. 



Strongly rhizomatous; only the middle sheaths with small blades; inflorescences 

 often only at the uppermost node and reduced to 1 to 3 spikelets; scales of spike- 

 lets with very short straight awns; the 3 expanded perianth parts tapering to their 

 acumens. . 



Rare in wet sand, s.e. Tex. (Aransas and San Patricio cos.), summer; coast- 

 wise, Fla. and Ga. to Tex.; Cuba. 



2. Fuirena squarrosa Michx. Fig. 185. 



Scales of spikelet with long often decurved awns; expanded perianth parts 

 tapering to the nonmucronate acumen which is often incurved to the style. 

 F. hispida Ell., F. breviseta Cov. 



Frequently in usually acid soils of marshes and bogs, e. and s.e. Tex., s. to 

 Aransas Co. and Okla. {Waterfall), summer; parts of e. U.S. w. to e. Okla. and 

 Tex.; Cuba, P.R. 



3. Fuirena simplex Vahl. Fig. 1 85. 



Scales of spikelet with long awns; expanded perianth parts variable but usually 

 apically blunt or refuse and dorsally just below the tip with a mucro or minute 

 awn. 



Frequent in wet areas, about springs, in shallow water on edge of ponds and 

 lakes, usually in calcareous mud, Okla. (Love, Stephens, McCurtain, Comanche 

 and Grady cos.), w. part of Tex., e. to n.-cen. Tex. and Rio Grande Plains and 

 N. M. (Eddy co.), later summer-fall; Guat. and Br. Hond. n.w. to Mo., Neb., 

 N.M., Son. and Baja Calif. 



365 



