208 



CYPERACEAE (SEDGE FAMILY) 



38. C. norvegica. 



40. C. tentlla. 



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

 minal i-i."^ <iii, long; i)engynia pale, about equaled 

 by the yeilowisli-brown blunt scales .... 

 Spikes approxiniatf ; the lowest less than 4 mm. thick; 

 plant weak, lax ; leaves involute. 0..O-1.5 mm. broad ; 

 perigvniu i>ale brown or drab. 



I'erigynia fusifoiiu Z% C. glareottn. 



Perigvnia ovoid (39) C. glareoHU, v. aviphi 



A . Staminate flowers borne at the top of the spikes k. 



k. I'erii.'-yina ellip.-oid-uvoid, scarcely compressed, nearly terete 

 k. Perigvnia compressed I. 



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



inflorescence m. 

 m. Rootstocks short and thick ; culm s 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 x>- 

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

 margins infiexed q. 

 q. Perigynia with minutely serrulate margins ; scales 

 blunt ; spikes mostly remote. 

 Perigynia quickly becoming squarrose. 

 Culms erect ; spikes 6-15-flowered 

 Culms loosely spreading ; spikes 2— 6-flowered 

 Perigynia ascending in fruit . . . . 

 Perigynia with smooth margins ; scales acuminate ; 

 spikes mostly approximate. 



Perigynia ovoid 



Perigynia lance-subulate .... (42) 



Perigjnia of essentially uniform (membranous) texture 

 throughout, not conspicuously spongj' below the 

 middle ; margins slightly if at all indexed r. 



Perigynia 4-0 mm. long 



Perigvnia less than 4 mm. long s. 

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

 1.5)— 4 cm. long. 



Perigynia distinctly nerved 



Perigvnia nerveless .... (44) C. 



8. Leaves and culms soft; heads 0.7-1.5 (rarely l.S) 

 cm. long. 

 Perigynia elliptic-ovate, broadest below 



middle, narrowest at base 

 Perigynia cordate-deltoid, broadest at the 

 date or subcordate base 

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



genu 



Q- 



r. 

 r. 



41. C. rosea. 



(41) C. rofiea, v. radiata. 



(41) C. rosea, v. minor. 



42. C. retrqfleoea. 

 C. retrqflexa, v. texensis. 



43. C. muricata. 



44. C. Muhlenbergii. 

 Muhlenbergii, v. ene/rvis. 



the 



cor- 



45. 

 46. 



C. cephalopJiora. 

 C. Leanenwm'thii. 



o. 



the outer face 



u. 



u. 



47. C. sparganoides. 



50. C. gravida. 



55. C. conjuncUi. 



Perigynia uniformly firm throughout, 

 nerveless or very faintly nerved u. 

 Perigynia wing-margined to the base ; spikes mostly 



distinct in a moniliform inflorescence . 

 Perigynia wing-margined only above the middle ; 

 spikes approximate in a cy'lindric 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) C. gravida, v. laxifolia. 

 Perigvnia lance-ovate, twice as long as the thin 



white scale 48. (7. cephaloidea. 



t. Perigynia spongy below the middle, the outer face 



prominentl}' ribbed 



n. Spikes yellowish or tawny when mature v. 



V. Perigvnia firm and uniform in texture, not spongy nor 

 "conspicuously inflated below, the beak shorter than 

 or barely equaling the body w. 

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

 inner face x. 

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

 ered ; scales acuminate, rarely awned y. 

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



wing-margins 



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

 like angles. 

 Beak nearly as long as the narrow-ovate body 



of the perigynium 



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

 orbicular body of the perigynium. 

 Culms 2—5 dm. high ; leaves subbasal 

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



Membranous or chartaceous band of the leaf-sheath 

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



y- 

 y- 



43. C. mv/ricaia. 



49. C. alopecoidea. 



50. C. gravida. 



C. gravida, v. laxifolia 



