CTPERACE^. (sedge FAMILY.) 503 



a. F. Idxa, Vahl. Culms slender (2'-12' high), weah, grooved and flat- 

 (ish ; leaves linear, flat, ciliate-denticulate, glaucous, sometimes haiiy ; spikes ovate, 

 acute (3" long) ; stamen 1 ; achenium 6 - Bobbed on each side, and with finer cross 

 lines, (t) (F. Baldwiniana, Torr. F. brizoides, Nees, &c.) — Low, mostly 

 clayey soil, Penn. to Illinois, and southward. July- Sept. 



§ 2. TBICHEL6STYLIS, Lestib. — %Ze S-cleft: achenium triangular: other- 

 vjise nearly as in § 1. 



3. F. autnmnalis, Roem. & Schult. Low (3'-9' high), in tufts; culms 

 flat, slender, difi^use or erect ; leaves flat, acute ; umbel compound ; spikes ob- 

 long, acute (l"-2" long) single or 2-3 in a cluster; the scales ovate-lanceo- 

 late, mucronate ; stamens 1-3. ® (Scirpus autumnalis, i.) — Low grounds, 

 Maine to Illinois, and southward. Aug. - Oct. 



i 3. 0NC6STTLIS, Martins. — Style 3-cleft, slender, its smaU bulb more or less 

 persistent on the apex of the triangular achenium. 



4. F. capiilaris. Low, densely tufted (3' -9' high); culm and loaves 

 nearly capillary, the latter all from the base, short ; umbel compound or pani- 

 cled; spikes (2" long) ovoid-oblong; stamens 2; achenium minutely virinkled, 

 very obtuse. Q) (Scirpus, L.) — Sandy fields, &c., common, especially south- 

 Ward. Aug. - Sept. 



9. FUIRENA, RottbolL Umbkella-Gbass. 



Spikes many-flowered, terete, clustered or solitary, axillary and terminal. 

 Scales imbricated in many ranks, awncd below the apex, all floriferous. Peri- 

 anth of 3 ovate or heart-shaped petaloid scales, mostly on claws, and usually 

 with as many alternate small bristles. Stamens 3. Style 3-cleft. Achenium 

 triangular, pointed with the persistent base of the style. Culms obtusely angu- 

 lar. (Named for G. Fuiren, a Danish botanist.) 



1. F. squarrdsa, Michx. Stem (1°- 2° high) leafy; leaves and sheaths 

 hairy ; spikes ovoid-oblong (J' long), clustered in heads, bristly with the spread- 

 ing awns of the scales ; perianth-scales ovate, awn-pointed, the interposed bris- 

 tles minute. — Var. ptjMiLA, Torr. is a dwarf form, l'-6' high, with 2-6 

 spikes ; perianth-scales ovate-lanceolate and oblanceolate. IJ. — Sandy wot 

 places, Massachusetts to Virginia, and sojithward ; also Michigan ; northward 

 mostly the small variety. Aug. 



lO. PSIl.OCARY'A, Torr. Bald-Rush. 



Spikes ovoid, terete, many-flowered ; the flowers all perfect. Scales imbri- 

 cated in several ranks ; the lower ones empty. Perianth none. Stamens usu- 

 ally 2. Style 2-cleft. Achenium doubly convex, more or less wiinkled trans- 

 versely, crowned with the persistent tubercle or dilated base of the style. — Culms 

 leafy ; the spikes in terminal and axillary cymes. (Name from ^iKos, bare, and 

 Kapia, nut, alluding to the absence of bristles.) 



1. P. scil'poides, Torr. Spikes 20 - 30-flowered ; scales oblong-ovate, 

 acute, tliestnut-colored; achenium obscurely wrinkled, beaked with the sword- 



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