176 CYPERACEAE 



Stamens 3. Style not swollen at the base, deciduous. Stigmas 3. Achene stalked or nearly 

 sessile, sharply 3-angled, acute or mucronate, smooth. 



Leaves reduced to sheaths without blades, except sometimes near the top of the stem. 

 Stems 2-6 dm. long : upper sheaths with barely any blades : achenes fully 1 mm. long. 



1. F. scirpoidea. 

 Stems 8-13 dm. long: upper sheaths with narrow blades: achenes barely l mm. long. 



2. F. longa. 

 Leaves with well-developed blades. 



Awn at the apex of the sepal, or wanting. 3. F. squarrosa. 



Awn arising from the back of the sepal below its apex. 4. F. simplex. 



1. Fuirena scirpoidea Michx. Rootstocks elongated : stems widely tufted, slender, 

 2-6 dm. tall, simple : leaves reduced to several sheaths 1-2 cm. long, with oblique mar- 

 gins : bracts of the involucre 2-6 mm. long, appressed to the spike, acute or cuspidate : 

 spikelets sessile, solitary or 2 or 3 together, oblong or ovoid-oblong, 5-12 mm. long, sessile: 

 scales broadened upward, abruptly pointed, each with an erect awn, several-ribbed : sepals 

 3 ; blades oblong to oval-oblong, about as long as the stalks : perianth bristles hispid, longer 

 than the stalks of the sepals : achenes 3-angled, oval -rhombic, constricted at both ends, fully 

 1 mm. long. 



In low sandy places, Georgia and Florida to Louisiana. Spring to fall. 



2. Fuirena Idnga Chapm. Rootstocks slender : stems loosely tufted, very slender, 

 8-15 dm. long, declining or reclining : leaves various, reduced to acute or acuminate sheaths 

 2.5-3 cm. long on the lower part of the stem, near the top of the stem with very narrow 

 blades as long as the sheaths or slightly longer : bracts of the involucre 8-16 mm. long, 

 acuminate : spikelets oblong-ovoid, 2-4 together, 10-15 mm. long : scales pubescent, with 

 awns about as long as the obovate body : sepals with ovate or suborbicular blades : perianth 

 bristles slightly hispid : achenes 3-angled, obovoid or oval, barely 1 mm. long. 



In low pine lands, western Florida. Summer and fall. 



3. Fuirena squarr6sa Michx. Rootstock short, sometimes tuber-bearing : stems 

 tufted, glabrous or nearly so, 5-50 cm. tall : leaf-blades flat, nearly or quite glabrous ; the 

 lower sheaths sometimes pubescent: spikelets sessile, solitary or 2-10 together in capitate 

 clusters, ovo;d or ovoid-oblong, 6-12 mm. long, about 5 mm. in diameter: scales ovate or 

 oblong, brown, pubescent, mostly obtuse, 3-nerved, each tipped with a stout, spreading or 

 recurved awn nearly as long as the body : sepals 3 ; blades oblong, long-stalked, usually 

 narrowed at both ends, the awn downwardly barbed or sometimes smooth : perianth-bris- 

 tles mostly longer than the achene. 



In wet meadows and marshes, Massachusetts to Florida and Louisiana, mostly near the coast. 

 Also in Michigan and Nebraska Summer and fall. A variety, F. squarrosa hlapida (Ell.) Chapm. with 

 retrorsely barbed bristles reaching to the middle of the achene or its tip, rhomboidal or deltoid-ovate, 

 truncate or cordate scales, each tapering into a short thick unbarbed awn or tip, ranges from New 

 York to Florida and Texas. Another variety, F. squarrosa breviseta Coville, with smooth perianth-bristles 

 not exceeding the stipe of the achene; oval or suborbieular scales rounded at the apex and with a 

 minute apiculation, ranges from North Carolina to Florida and Texas. 



4. Fuirena simplex Vahl. Similar to the preceding species in habit. Stems 1-5 dm- 

 tall, glabrous : leaf -blades flat, glabrous or ciliate : scales numerous, each tipped with a 

 spreading or reflexed awn : sepals 3 ; blades ovate-oblong, obtuse and usually notched at the 

 apex, the awn smooth or downwardly barbed : perianth-bristles retrorsely hispid, equalling 

 or exceeding the sessile or short-stalked achene. 



In moist soil, Nebraska to Texas and Mexico. Summer and fall. A form from the valley of the 

 lower Rio Grande, Texas, larger throughout and with spikelets 2 cm. long is F. simplex macrostdchya 

 (Britton) Coville. 



8. SCIRPUS L. 



Annual or perennial very small or very large caulescent or scapose herbs, 'the leaves 

 sometimes reduced to basal sheaths. Spikelets terete or somewhat flattened, solitary, capi- 

 tate, spicate or umbellate, subtended by an involucre of 1-several bracts, or the involucre 

 wanting in some species. Scales spirally imbricated, the 1-3 lower sometimes empty. 

 Flowers perfect. Perianth of 1-6 slender or rigid, barbed, pubescent or smooth bristles, 

 or rarely none. Stamens 2-3. Style not swollen at the base, wholly deciduous from the 

 achene, or its base persistent as a subulate tip. Stigmas 2-3. Achene triangular, lenticular 

 or plano-convex. BULRUSH. CLUB-RUSH. 



Involucre of a single bract, or wanting. 



Spikelets solitary, or rarely 2 in No. 5, terminal. 



Involucre wanting. 1. S. nanus. 



Involucre present, of a single bract. 



Perianth-bristles present : scales not keeled. 



Scapes terete : upper sheath with a subulate blade : perianth-bristles 

 i 2. S. caespitosus. 



