5G0 CTPERACE^. (sedge FAMILY.) 



§ i. Spike more or less flattmfd , thicker than the slende-r or cnpiljanj culm,fem-many- 

 Jlowered ; the thin memhranaceotis scales somewhiit 2 ~3-raii/ced : stifle S-chft: 

 bristles of the perianth 3 - G,fiar/ilc or fuijacious. Sntull or dulicate species, dif- 

 fering from the lust subdiciaion chiijlij in ihejlaltish spikes. (CH.ETOCYi'iiRL'S, 

 Nees.) 



* Acheniitm tumid, obscurely triangular, many-ribbed on the sides. 



16. E. acicularis, R. Br. Culms finely capillary (2'- 8' long), more or 

 less 4-anj,'ular ; spike 3 - 9-flowered ; scales ovate-oblong, rather obtuse (greenish 

 with purple sides); achenium obovatc-oblong, with 3-ribbed angles and 2-3 

 times as many smaller intermediate ribs, also transversely striate, longer than 

 the 3-4 very fugacious bristles; tubercle conical-triangular. (S. trichodes, 

 Mulil., &c.) — Muddy shores : common. (Eu.) 



* * Achenium triangular, with smooth and even sides. 



17. E. pygmsea, Torr. Culms bristle-like, flattened and grooved (1'- 2' 

 high) ; spike oc/ite, 3 - S-flowred; scales ovate (greenish), the upper rather acute ; 

 achenium ovoid, acutely triangular, smooth and shining, ti[)ped with a minute 

 tubercle ; bristles mostly longer than the fruit, sometimes wanting. (S. pusillus, 

 Vuhl?) —Brackish marshes and brackish river-banks. 



8. SCIRPUS, L. Bulrush or Club-Rush. (PI. 3.) 



Spikes several - many-flowered, solitary or in a terminal cluster which (except 

 in No. 1) is subtended by a 1 -several-leaved involucre (this when simple often 

 appearing like a continuation of the culm), terete, the scales being regularly 

 imbricated all round in many or several ranks, or rarely somewhat compressed, 

 the fewer scales inclining to be 2-ranked. Flowers under all the scales, or all 

 but one or two of the lowest, all perfect. Perianth of 3-6 (straight or rarely 

 tortuous) bristles, or sometimes wanting. Stamens mostly 3. Style 2-3-cleft, 

 simple, not bulbous at the base, wholly deciduous, or sometimes leaving a tip or 

 point to the lenticular or triangular achenium. — Culms sheathed at the base; 

 the sheaths usually leaf-bearing. Perennials, except No. 8-9; flowering in 

 summer. (The Latin name of the Bulrush.) 



§ 1. SCIRPUS proper (including Isolepis, which simply wants the bristles). 

 Bristles when present rigid, not elongated and contorted or exserled after flowering, 

 mostly barbed downivards. 

 * Spike solitary, few-flowered, small, oflen flatfish: achenium triangular, smooth. 

 *- No involucral leaf or bract and no leaves below : base of style indurated and persist- 

 ent, but continuous with the achenium. ( Transition to Eleocharis and Blysmus. ) 

 1. S. paueifldrus, Lightfoot. Culms striate-angled, very slender 

 (3' -9' high), scarcely tufted, on slender running rootstocks, at the base with a 

 short truncate sheath ; scales of the ovate spike evidently 2-ranked, chestnut- 

 brown, pointless, all flower-bearing, the two lower Larger ; bristles 3-6, down- 

 wardly barbed, about the length of the conspicuously beak-pointed triangular 

 achenium. (S. Tixothryon, Ehrh. Blysmus pauciflorus, Corar/. ) — Very wet 

 places. New York (Jefferson Co., Dr. Crnwe, & Herkimer Co., ./. A Paine) to 

 N. Illinois 'D Vaspy), Michigan, and northwestward. (Eu.) 



i 



