CTPERACE^:. (SEDGE FAMILY.) 577 



Var. endrvis, Boott. Scales sometimes pointless ; perigynia nearly or wholly 

 nerveless ; spikes often bractless. Hudson River, New York, J. L. Russell. 

 Distinguished from C. cephaloidea by its rigid culm, narrower leaves, and 

 firmer perigynium, spongy at the base. 



25. C. rbsea, Schk. Spikes 4-8, the 2 uppermost approximate, the others all 

 distinct, and the lowest often remote ; perigynia oblong (about 8-10 in each spike), 

 narrow at the base, widely diverging at maturity, twice, as long as the broadly 

 ovate obtuse scale. Var. MINOR, Boott, has the 4 - 6 spikes smaller and more 

 separated, the scales less obtuse and with a rough mucronate point ; perigynia 

 more erect ; leaves narrower. Var. RADIATA, Dew, is still more slender, 

 almost capillary, and has only 3 or 4 remote and 3-4-flowered spikes. (C. 

 neglecta, Tuckenn.) Moist woods and meadows: common. 



26. C. retrofl6xa, Muhl. Spikes 3 - 6, all approximate, the 1 -2 lowest dis- 

 tinct but not remote ; perigynia (about 5 - 7 in each spike) ovate, or ovate-lanceo- 

 late, smooth on the margin and beak, not much exceeding the ovate-lanceolate pointed 

 scale, widely spreading or reflexed at maturity. (C. rosea, var. retroflexa, Torr., 

 Gyp.) Copses and moist meadows : less common than the last, from which it 

 is distinguished by the smaller approximate spikes, longer and sharper scales, 

 and especially, from every species in this subsection, by the smooth perigynium. 



# # # * # Perigynia plano-convex, without a beak, of a thick and leathery texture, 



prominently nerved, smooth (except on the angles), with a minute and entire 

 or slightly notched white membranaceous point : achenium conformed to the peri- 

 gynium, crowned with the short thick style : bracts like the scales (brown), 

 the lowest with a prolonged point : rootstock creeping. CHORDORHIZ^E. 



27. C. chordorhiza, Ehrh. Culms branching from the long creeping root- 

 stock (4' -9' high), smooth and naked above, clothed at the base with short ap- 

 pressed leaves ; spikes in an ovoid head; perigynia ovate, a little longer than the 

 scale. Cold bogs, New York to Wisconsin, and northward. (Eu.) 



28. C. tenella, Schk. Spikes 2-6, very small, rather remote, or the upper 

 approximate, with 2 or 3, rarely 4, fertile /lowers ; perigynia ovate, twice as long 

 as the scale. (C. loliacea, Schk. suppl, not of L. C. disperma, Dew. C. gra- 

 cilis, Ed. 1, not of Ehrh.) Cold swamps, New England to Penn., Wisconsin, 

 and northward. A slender species, 6'- 12' high, with long grassy leaves, 

 growing in loose tufts. (Eu.) 



3. Spikes pistillate above, staminate at the base. 



* Spikes roundish-ovoid, rather small, more or less distant on the zigzag axis (closely 



aggregated in No. 30) : perigynia plano-convex, smooth, pale green, becoming 

 whitish or silvery : scales white and membranaceous ; the bracts resembling 

 them, or prolonged and bristle-shaped. CANESCENTES. 



- Perigynia mostly somewhat thickened and leathery, distinctly nerved, and with a 

 smooth or minutely serrulate short point, entire or slightly notched at the apex. 



29. C. trisp6rma, Dew. Spikes 2 -3, very small, with about 3 fertile flow- 

 ers, remote, the lowest with a long bract ; perigynia oblong, with numerous slender 

 nerves, longer than the scale. Cold swamps and woods, especially on moun- 

 tains, New England to Penn., Michigan, and northward. Resembling the last, 

 but larger spikes and fruit, and weak spreading culms, l-2 long. 



37 



