402 CYPERACEiE. 



ovate, acute, membranaceous ; style long, rostrate, persistent, much dilated 

 at the base, and decurrent at the edges of the tumid rugose achenium. 

 (To7r. Ctjp.) 



Borders of a pond near North Providence, R. I. Near Boston and New Bed- 

 ford, Mass. T. A. Greene and Dr. H. Little. Culm obtusely triangular, smooth, 

 leafy. Leaves 6 — 8 inches long, grassy. Cymes pedunculate, one terminal and 

 one from the sheath of each leaf, spreading. Spikes 3 — 4 lines long, 20 — 30- 

 flovvered. Bristles entirely wanting. Scirpus-HJte Psuocarpa. 



VII. ScLERE^. Flowers diclinous. Fertile spikelets 1- or rarely 

 '■I-Jlowered. . Scales fasciculate ; the lower ones empty, often seated in 

 a cup or torus, Perigynium of 3 scales, often wanting. Achenium 

 nut-like. 



16. SCLERIA, Z/mll— Nut Rush. ^ 



(From the Greek crK'Knpoi, hard ; in allusion to the hard bone-like achenium.) 

 Monoecious. Fertile spikelets 1 -flowered ; the sterile seve- 

 ral-flowered. Scales 2 — 6. Disk shallow, saucer-like or lobed. 

 Perigynium coriaceous or crustaceous, sometimes wanting. 

 Achenium globose or ovoid. 



* With a perigynium. 



1. iS. reticularis Mich. : culm erect, rough on the angles below; fascicles 

 lateral and terminal, remote, loose; achenium globose, reticulated and 

 deeply pitted between the lines ; perigynium 3-lobed. 



Sandy sv^-amps. Long Island, N. Y. Torr. S. to Flor. Aug. %..—Culm 

 12 — 15 inches high, triangular. Leaves smooth, flat. Spikelets in pairs. Scales 

 smooth; the sterile lanceolate; the fertile ovate mucronate. 



Reticulated Nut Rush. 



2. S. laxa Torr. : culm weak, somewhat diffuse, nearly smooth ; fasci- 

 cles lateral and terminal, remote, on long slender peduncles, loosely flow- 

 ered ; scales and bracts smooth ; achenium globose, pitted and marked in a 

 romewhat spiral manner with transverse hairy wrinkles ; perigynium 3- 

 lobed. »S. reticularis Muhl. 



Sandy swamps. N. Y. to Flor. Aug. %.—Culm 12—18 inches high, 

 acutely triangular. Leaves flat, smooth. Spikelets in pairs, distant. 



Loose-Jlowered Nut Rush. 



3. S. iriglamerata Mich. : culm acutely triangular, rough ; leaves broad- 

 linear, somewhat hairy ; fascicles lateral and terminal, triglomerate ; bracts 

 ciliate ; scales cuspidate ; achenium ovoid-globose, smooth and polished ; 

 perigynium annular. 



Swamps and moist grounds. Ver. to Flor. W. to Ark. June, July. 1].. — • 

 Culm 3 — 4 feet high, leafy. Leaves 2 — 3 lines wide, rough on the margin, hairy 

 beneath. Scales purplish. Achenium large and white. 



Three-clustered Nut Rush. 



4. (S. paucifora Muhl. : culm triangular, slender, smoothish ; leaves nar- 

 row-linear, with pubescent sheaths ; fascicles lateral and terminal, few- 

 flowered, the lateral on long peduncles; bracts ciliate; scales smoothish; 

 achenium globose-ovoid, warty ; perigynium of 6 tooth-like processes. 



