CYPERACEAE (SEDGE FAMILY) 199 



14. RYNCH6SPORA Vahl. BEAK RUSH 



Spikelets panicled or variously clustered, ovate, globular, or spindle-shaped, 

 terete, or sometimes flattish ; but the scales open or barely concave (not boat- 

 shaped nor keeled) ; the lower commonly loosely imbricated and empty, the 

 uppermost often subtending imperfect flowers. Perianth of bristles. Stamens 

 mostly 3. Achene lenticular, globular, or flat, crowned with a conspicuous 

 tubercle or beak consisting of the persistent indurated base or even of the greater 

 part of the style. Chiefly perennials, with more or less 

 triangular and leafy culms ; the spikelets in terminal and 

 axillary clusters ; flowering in summer. (Name composed 

 of ptyxos, a snout, and cnropd, a seed, from the beaked 

 achene.) 



1. Spikelets lanceolate, acuminate, in fruit flatfish, 

 cymose-panicled, of only one perfect and 1-4 staminate 

 flowers ; scales few ; bristles rigid, minutely scabrous 

 upward; style simple or barely 2-toothed, filiform 



and gradually thickened downward, in 



fruit persistent as an exserted slender 



awl-shaped upwardly roughened beak, 



several times longer than the smooth 



flat obovate achene ; coarse perennials ; 



spikelets in flower 1-1.5, in fruit (in- 

 cluding the projecting beak) 2-3 cm. 



long. 



1. R. corniculata (Lam.) Gray. 



(HORNED RUSH.) Culm 0.5-2 m. high; 313 ' R " c lata - 

 leaves 0.6-2 cm. wide ; cymes decompound, diffuse ; bristles 

 awl-shaped, stout, unequal, shorter than the achene. Wet 

 places on the coastal plain, Del. and Pa. to Fla. and Tex., 

 locally northw. in the Miss. Basin to Mo., Ind., and 0. 

 June-Sept. FIG. 313. 



2. R. macrostachya Torr. Erect and rather stiff ; the 

 glomerules mostly of 10-50 spikelets, strongly ascending, 

 sessile or on few short rays; bristles capillary, twice the 

 length of the achene. Borders of ponds, Mass, to Fla. and 

 Tex., locally northw. in the Miss. Basin to Kan. and Ind. 



814. R.macrostachya. Aug.-Oct. FIG. 314 



\ ar. mundata (Oakes) Fernald. Cyme loosely decom- 

 pound, the numerous rays wide-spreading or flexuous ; the spikelets solitary 

 or 2-6 in loose glomerules. (Var. patula Chapm.) Mass, to Fla. 



2. Spikelets terete or biconvex, few-many-flowered ; style conspicuously 2- 

 cleft, its base only forming the tubercle of the mostly lenticular achene ; 

 bristles usually present, merely rough or barbed-denticulate (rarely plu- 

 mose). 



* Achene transversely wrinkled; bristles mostly 6, upwardly denticulate. 



3. R. cymbsa Ell. Culm slender 0.3-1 m. high, triangular; 

 leaves linear (1-4 mm. wide)', cymes corymbose, the brown spike- 

 lets crowded and clustered ; achene round-obovoid, faintly wrinkled, 

 twice the length of the bristles, four times the 

 length of the depressed-conical narrow tubercle. 

 Low grounds, N. J., Pa., 111., and south w. June- 

 316 R com Aug ' (W. L, S. A.) FIG. 315. 



nressa 4 - R comprSssa Carey. Similar; culm rather 



stout ; leaves pale and firm, 3-7 mm. wide ; achene 



strongly wrinkled, the tubercle with broad depressed thin-edged 



base. Ga. and Fla. to La., northw. in the low country to Mo. 



July. FlG. 316. 815. K. cyrnosa. 



