CYPERACEAE (SEDGE FAMILY) 



191 



1-5 ovoid aciitish spikelets (0.5-1 cm. long); involucral leaf always 

 erect ; scales oblong-oval ; style 2-cleft ; bristles 1 or 2 miiinte. 

 rudiments or none ; achene cuneate-obovate. — Wet shores, local. 

 Me. to Pa., 111., Mich., and Out. July-Sept. Fig. 285. Var. 

 set6sus Fernald. Perianth of 4 or 5 slender retrorsely barbed 

 bristles, mostly exceeding the acheues. — Me.; 

 Mass. ; and 111. 



12. S. americanus Pers. Running rootstocks 

 long and stout ; culms sharply S-angled through- 

 out (0.2-1 m. high) with concave Sides; leaves „,. ^ . . , ,, 

 1-8, elongated (1-8 dm. long), keeled and chau- ^''- ^-^"''^^^ 

 neled ; involucral leaf pointed; spikelets 1-6, capitate, ovoid, 

 mostly 0.5-1 cm. long ; scales ovate, sparingly ciliate, 2-cleft 

 at the apex ; anthers tipped with an awl-shaped minutely fringeA 

 appendage; style 2-cleft (rarely 3-cleft); bristles 2-6, shorter 

 than the smooth achene. (^8. pungens Vahl.) — Borders ol 

 286 S americanus ^^^^ ^"^^^ fresh ponds and streams, temperate N. A. Aiig.- 

 ' * * Oct. (Eu., S. A.) Fig. 286. 



13. S. Torreyi Olney. Bootstocks slender and weak; culm ^-angled, with 

 concave sides, rather slender (0.4-1.5 m. high), leafy at base; leaves 2 or 3, more 

 than half the length of the culm, triangular-channeled, slender ; 

 involucral leaf blunt; spikelets 1-4, oblong or spindle-shaped, 

 ac7ite, distinct, 1-1.5 cm. long ; scales ovate, smooth, barely mu- 

 cronate ; style o-cleft ; bristles longer than the unequally triangular 

 very sinooth long-pointed achene. — Borders of ponds, brackish 

 and fresh, Me. to Pa., la., and Man. Aug., Sept. 

 Fig. 287. 



14. S. 01nd5d Gray. Culm ^-wing -angled, with 

 deeply excavated sides, stout (0.5-2 m. high), the 

 upper sheath bearing a triangular leaf or none; 

 spikelets 6-12, closely capitate, ovoid, obtuse, over- 

 topped by the short involucral leaf ; scales orbicular, 237 s Torrej-i. 

 smooth, the inconspicuous mucronate point shorter 

 than the scarious apex ; anthers with a vei-y short and blunt 

 minutely bearded tip; style 2-cleft; bristles 6, scarcely equaling 

 the narrowly obovate plano-convex and mucronate achene. — Salt 

 oaa « ni,,-.^- marshes, N. H. to Fla. ; also in Mich., and on the Pacific coast. 

 288. S.Olneyi. j^jy_g^p^^ (W.I.) Fig. 288. 



15. S. mucronXtus L. Resembling the last, 3-9 dm. high ; involucral leaf 



divergent; spikelets numerous in a dense cluster, oblong-ovoid; scales ovate, 

 mucronate, firm, scarcely at all scarious; style S-cleft; 

 achene unequally trigonous, broadly obovate. — In a 

 single locality in Delaware Co., Pa.; probably introd. 

 from s. Eu. 



16. S. etuberculatus (Steud.) Ktze. Cuhn (1-2 m.high) 

 Z-angled, usually sharply so above, obtusely below, the 

 sheath at base extended into a long slender triangular and 

 channeled leaf; involucral leaf similar (1-2.5 dm. long), 

 continuing the culm ; spikelets cylindric (1-2 cm. long), 

 single or sometimes proliferously 2 or 3 together, nodding 

 on the apex of the 5-9 long filiform and flattened peduncles 

 or rays of the dichotomous umbel-like corymb, or the 

 central one nearly sessile ; scales loosely imbricated, 

 oblong-ovate, acute, pale, thin and scarious, with a green- 

 ish nerved back; bristles 6, firm, furnished above with 

 spreading hairs rather than barbs, equaling the slender 

 abrupt beak of the obovoid-triangular shining achene 

 (4 mm. long). {S. Canbyi Gray; S. cylindrictis Erilton.) 

 — Swamps and ponds, Md. to Fla., etc. June-Aug. 

 Fig. 289. 289. 8. etuberoulatus. 



