^08 



CYPERACEAE (^SEDGE EAMILY^ 



. 39. C. glareoaa. 



C. glareoaa, v. amphigena 



40. C. tenella. 



41. C. rosea. 



(41) C. rosea, v. radiata. 



(41) O. rosea, v. mzTwr. 



Spikes distinct; the lowest 4^5 mm. thick; the ter- 

 minal i~].ft cm. long; perigynia pale, about equaled 

 by the yeilowiah-brovvn blunt scales .... 3^. C. norvegica. 

 Spikes approximate; tjie lowest less than 4 mm. thick; 

 plant weak, lax ; leaves involute, 0.5-1.5 mm. broad ; 

 perigynia pale brown or drab. 

 Perigynia fusiform ... 



Perigynia ()\-(ji<l i 



A. Staminate flowers borne at the top of the Spikes 7c. 

 /,'. Heri[,'yiiia eilipsoid-ovoid. scarcely compressed, nearly terete 

 /i\ Pei-igynia compressed l. 



I. Spikes 2 or more In a simple or compound spicate or paniculate 



inflorescence m. 

 ■m. Rootstocks short and thick ; culms in terminal tufts or stools n. 

 n. Spikes green or nearly so when mature (becoming brown 

 only when over-ripe) o. 

 o. Broadest leaves 1-4.5 mm. wide 2^- 

 p. Perigynia very spongy below the middle, the nerve-like 

 margins ihflexed q. 

 q. Perigynia with minutely serrulate margins ; scales 

 blunt; splkeu mostly remote. 

 Perigynia quickly becoming squarrose. 

 Culms erect ; spikes 6-15-ilowered 

 Culms loosely spreading ; spikes 2— 6- flowered 

 Perigynia ascending in fruit .... 



q. Perigynia with smooth margins; scales acuminate; 

 spikes mostly approximate. 



Perigynia ovoid , 42. (?. retrojlexa. 



Perigynia lance-subulate .... (42) C. reUqflexa, v. i 



p. Perigynia of essentially uniform (membranous) texture 

 throughout, not conspicuously spongy below the 

 middle ; margins slightly if at all inflexed r. 

 T. Perigynia 4-6 mm. long . .... 48. C.murioata. 



r, Perigynia less than 4 mm. long s. 



8. Leaves and culms stiff and wiry ; heads 2 (rarely 

 1.5)-4 cm. long. 



Perigynia distinctly nerved 44. (7. Muhlenhergii. 



Perigynia nerveless ..... (44) C. Muhlenhergii, v. enervis. 



B. Leaves and ciTlms soft; heads 0.7-1.5 (rarely 1.8) 

 cm. long. 

 Perigynia elliptic-ovate, broadest below the 



middle, narrowest at base 

 Perigynia cordate-deltoid, broadest at the cor- 

 date or subcordate base 

 o. Leaves 5-10 (the narrowest rarely 4.5) mm. wide t. 



t. Perigynia uniformly firm throughout, the outer face 

 nerveless or very faintly nerved u. 

 u. Perigynia wing-margined to the base; spikes mostly 



distinct in a moniliform inflorescence . 

 u, Perigynia wing-margined only above the middle ; 

 spikes approximate in a cylindric or ovoid head. 

 Perigynia broad-ovate to suborbicular, nearly 

 equaled by the long-pointed scales. 

 Culms 2-5 dm, high ; leaves subbasal 

 Culms 6-12 dm. high ; leaves remote . (50) 



Perigynia lance-ovate, twice as long as the thin 



white scale . . 



t. Perigynia spongy below the middle, the outer face 



prominently ribbed 



71,. Spikes yellowish or tawny when mature v. 



-v. Perigynia firm and uniform in texture, not spongy nor 

 conspicuously infiated below, the beak shorter than 

 or barely equaling the body w. 

 w. Perigynia straw-color, thin, distinctly flattened on the 

 inner face os. 

 X. Membranous band of the leaf-sheath not cross-puck- 

 ered; scales acuminate, rarely awned y. 

 y. Leaves 2-3 mm. wide ; culms firm, without thin 



wing-margins 



y. Leaves 4-S mm. wide ; culms soft, with almost wing- 

 like angles. 

 Beak nearly as long as the narrow-ovate body 



of the perigynmm 



Beak one third as long as the broad-ovate or sub- 

 orbicular body of the perigynium. 

 Culms 2-5 dm. high ; leaves subbasal 

 Culms C-12 dm. high ; leaves remote (50) 



CB. Membranous or chartaceous band of the leaf-sheath 

 cross -puckered, at least in age ; scales awn-tipped. 



45. 

 46. 



0. cephalophora. 

 C. Zeavenworthii. 



47. C. sparganoides. 



50. C. gravida. 

 C. gravida, v. laxifolicu 



48. 

 55. 



C. cephaloidea. 

 0. conjuncta. 



48. C- muricata. 



49. C, alopecoidea. 



50. C. gravida. 

 C. gravida, v. lanifolia 



