THE GENUS CAREX IN CALIFORNIA 13 



Beak of perigynium terete toward apex, the upper 1-3 mm. smooth or nearly so. 



Perigynia appressed, nearly or entirely covered by scales, the beaks not conspicuous in 

 the spikes. 



Culms slender; spikes in a flexuous nodding head 35. C. praticola. 



Culms stiff; spikes approximate in an erect head. 



Culms 1-6 dm. high, the leaves not bunched near base; blades 2-3 mm. 



wide, flat; beak of perigynium not hyaline at orifice. 36. C. Tracyi. 

 Culms 1-3 dm. high, the leaves bunched near base; blades 1.5-2 mm. wide, 

 more or less involute; perigynium beak hyaline at orifice. 



Perjgynia oblong-ovate, rather strongly margined 37. C. phceocephala. 



Perigynia linear-lanceolate, very narrowly margined, boat-shaped 



38. C. leporinella. 



Upper part of perigynia conspicuous in the spikes, not covered by scales. 

 Perigynia lanceolate, 5.5-8.5 mm. in length, 3-5 times as long as wide. 



Spikes about three, not capitate; scales little more than J^ length of perigynia. 



39. C. Davyi. 



Spikes 6-12, capitate; scales equaling bodies of perigynia 40. C. specified. 



Perigynia ovate or if lanceolate shorter than 5.5 mm. in length. 

 Lower bracts leaflet-like, much exceeding head. 



Perigynia strongly nerved ventrally, the beak ferruginous at orifice, 



bidentate 41. C. unilateralis. 



Perigynia obscurely nerved ventrally, the beak hyaline at orifice, bi- 



dentulate 42. C. athroatachya. 



Lower bracts scale-like, much shorter than or slightly exceeding head. 

 Perigynia with membranaceous or submembranaceous walls. 

 Perigynia thin and flat save where distended by achene. 



Perigynia 3.5-5 mm. long; culms slender 43. C. festuella. 



Perigynia 4.5-6 mm. long; culms low, ascending or decumbent 



44. C. nubicola. 



Perigynia strongly plano-convex at maturity. 



Perigynia nerveless ventrally or with impressed nerves 



45. C. pachystachya. 



Perigynia with conspicuous raised nerves on inner face. 



Perigynia conspicuously hyaline-tipped; spikes densely capi- 

 tate..... 46. C. abrupta. 



Perigynia reddish-tipped; spikes more or less strongly sep- 

 arate 47. C. mariposana. 



perigynia with thick, firm walls. 



Perigynia very small (2.25-3.5 mm. long). 



Margins of perigynia entire (or very obscurely subserrulate) 



48. C. Integra. 



Margins of perigynia strongly serrulate 49. C. tenerce/ormis. 



Perigynia longer (3.5 mm. long or more). 



Lower biacts (at least) strongly amplectant; beaks of perigynia 



and scales little reddish-tinged 50. C. amplectens. 



Bracts not amplectant; beaks of perigynia and scales strongly 

 reddish-tinged. 

 Perigynia strongly nerved ventrally, the nerves prominent.... 



51. C. Harfordii. 



Perigynia nerveless or very obscurely nerved ventrally. 



Perigynia with a few raised nerves dorsally; coastal 

 species. 

 Spikes strongly capitate; leaf-blades averaging 2.5-3 



mm. wide; culms 3.5-12 dm. high 



52. C. sub-bracteata. 



Spikes not capitate, the head slender; leaf-blades 

 averaging 1.5-2 mm. wide; culms 1-6 dm. 



high 53. C. gracilior. 



Perigynia many-striate or with impressed nerves dor- 

 sally; species of the Sierra Nevada. 

 Spikes not few-flowered; culms slender; leaves not 



clustered, the blades elongated 



54. C. pachycarpa. 



Spikes 6-12-flowered; culms stiff; leaves clustered, 

 the blades short 55. C paucifructus. 



