SEDGE FAMILY 43 



Spikes slender, few-flowered; perigynia 4 

 mm. long or less, not inflated, the beak 

 not becoming bidentate. 



34. C.\PILLARES. 



Spikes dense, many-flowered ; perigyma longer, 

 more or less inflated, the beak becoming 

 bidentate. 3.5. Longiro.stres. 



Scales dark-tinged. 36. Frigid.\e. 



Lowest bract sheathless, or sheathing; if sheathing, peri- 

 gynia strongly bidentate with stiff teeth. 

 Foliage pubescent; perigynia not bidentate. 



37. Pallescentes. 

 Foliage glabrous, or if rarely pubescent, perigynia bi- 

 dentate. 

 Perigynia rough-papillose. 38. Anomalae. 

 Perigynia at most granular-roughened. 



Perigynia beakless or very short-beaked; achenes 

 triangular. 

 Perigynia glaucous. 39. Limosae. 

 Perigynia not glaucous. 40. Atrat.\e. 

 Perigynia with strongly bidentate beak, or if not, 

 achenes lenticular. 

 Achenes lenticular; perigynia dull. 



41. Acut.\e. 



Achenes triangular, or if rarely lenticular, 

 perigynia shining. 

 Perigynia coriaceous, little if at all inflated, 

 often pubescent; bracts sheathless. 



42. HlRT.-VE. 



Perigcnia glabrous, often inflated; if rarely 

 Peoriaceous, the bracts sheathing, 

 rigynia little inflated; lower bract 

 strongly sheathing. 



43. EXTENSAE. 



Perigynia little to much inflated; lower 

 bract not strongly sheathing. 

 Spike one. 44. Paupiflorae. 

 Spikes more than one. 



Perigynia finely and closely ribbed. 

 45. Pseudo-Cypereae. 

 Perigynia coarsely ribbed or nerve- 

 less. 46. Physocarpae. 

 1. Nardinae. 

 Represented by one species in our range. 1. C. Hepburnii. 



2. Infi^tae. 

 Represented by one species in our range. 2. C. Engelmannii. 



3. Athrochlaenae. 

 Densely cespitose; leaf-blades involute, 1 mm. wide; staminate flowers few; perigynia 



erect until full maturity. 3. C. pi/renaica. 



Short-stoloniferous ; leaf-blades flat, 1.5 mm. wide or more; staminate flowers conspicuous; 

 perigynia early deflexed. 4. C. nigricans. 



4. Capitatae. 

 Represented by one species. 5. C. capitata. 



5. DiOICAE. 



Represented by one species in our range. 6. C. gynocrates. 



6. FOETIDAE. 



Leaf-blades 2-3.5 mm. wide; perigynium little exceeding the scale at maturity. 



7. C. vernacula. 

 Leaf-blades 1.5 mm. wide or less; perigynium much exceeding the scale at maturity. 



Perigynia membranous, not stipitate. 8. C. perglobosa. 



Perigynia not membranous, stipitate. 9. C. incurviformis. 



7. DrviSAE. 

 Rootstocks slender, light brownish; culms obtusely triangular, normally smooth; leaf- 

 blades narrowly involute. 

 Perigynia long-beaked; heads dioecious or nearly so. 10. C. Douglasii. 



Perigynia short-beaked; heads androgynous. 11. C. slcnophylla. 



Rootstocks stout; culms acutely triangular, normally rough above. 

 PerigjTiia not strongly nerved ventrally; leaf-sheaths hyalme. 



Perigynia chestnut, thick, the beak about one-flfth as long as the body. 



12. C. simuiala. 

 Perigynia blackish in age, plano-convex, the beak one-third to one-half as long as 

 the body. 13. C. praegracilis. 



Perigynia strongly nerved ventrally; upper leaf-sheaths green-striate opposite the 

 blades. 14. C. Sarlwellii. 



8. Chordorrhizae. 

 Represented by one species in our range. 15. C. chordorrhiza. 



9. Arenariae. 

 Represented by one species in our rajige. 16. C. siccata. 



