CYPEEACEAE. 



51 



than 3 mm. long : spikes oblong or linear-oblong. 

 Fertile culm-blades usually 3-5, 2-3.5 mm. wide : peri- 



gynia less than 3 mm. long: spikes linear. 

 Perigynium-beak straight, prominent, %-% length of body. 



XIII. LAXIFLORAE. 



Perigynia acutely triangular, short-tapering at the base. 

 Leaf-blades very smooth (except edges), the larger ones 

 12 mm. wide or more, those of fertile culm much 

 smaller than those of the sterile : perigynia smooth. 

 Leaf -blades hispidulpus on veins, 10 mm. wide or less ; 

 those of fertile culm moderately smaller than 

 those of the sterile : perigynia minutely roughened. 

 Perigynia short-beaked : second bract and leaves 

 usually exceeding culm : blades 2.5-5 mm. wide, 

 erect. 



Perigynia beakless or nearly so; second bract and 

 leaves usually exceeded by the culm ; blades 4-8 

 mm. wide, spreading. 

 Perigynia obtusely triangular, long-tapering at the base, 



smooth. 

 Pistillate scales very truncate ; larger blades 15-40 



mm. wide. 

 Pistillate scales acuminate to strongly cuspidate : larger 



blades narrower. 



Spikes elongate, 8-20-flowered, the lower ones nor- 

 mally on erect, stiff peduncles. 

 Perigynia obovoid ; beak abruptly bent, minute : 

 sterile shoots developing conspicuous culms. 

 Culms stout : sheaths loose, the margins 

 crisped : staminate spike short-stalked or 

 sessile. 



Culms slender: sheaths rather tight, the 

 margins little if at all crisped: staminate 

 spike long- or rarely short-stalked. 

 Perigynia obovoid or fusiform, with straight or 

 oblique conspicuous beaks : sterile shoots 

 reduced to tufts of leaves. 



Spikes short, 5-10-flowered, the lower ones on capil- 

 lary, spreading or drooping peduncles. 



XIV. GBANULARES. 

 A single species in our range. 



XV. OLIGOCARPAE. 



Sheaths smooth : perigynia 2.5-4 mm. long. 

 Sheaths rough-pubescent : perigynia 4.5-5 mm. long. 



31. C. MeadU. 



32. O. tetanica. 



33. C. polymorpha. 



34. C. platyphylla. 



35. C. digitalis. 



36. C. laxiculmis. 



37. C, albursina. 



38. C. Uanda. 



39. C. laxiflora. 



40. C. anceps. 



41. C. styloflexa. 



42. C. granularis. 



43. C. oligocarpa. 



44. C. HitchcocJciana. 



XVI. GRISEAE. 



Perigynia elliptic, 1.5 mm. wide : leaf-blades 4 mm. wide 



or less : bract-sheaths rough, and peduncles very rough. 45. C. conoidea. 

 Perigynia oblong, 2 mm. wide : leaf-blades 3-7 mm. wide : 



bract-sheaths smooth, and peduncles nearly so. 

 Leaf -blades not glaucous : larger spikes usually less 

 than 12-flowered : lower scales usually equalling 

 perigynia. 46. C. grisea. 



Leaf-blades glaucous : larger spikes more than 12- 

 flowered : lower scales shorter than perigynia. 47. C. glaucodea. 



XVII. GRACILLIMAE. 



Plants glabrous : perigynia 4 mm. long or less. 



Perigynia rounded at the apex, beakless. 48. C. gracillima. 



Perigynia sharp-pointed at the apex, short-beaked. 49. C. prasina. 



Sheaths, and often foliage, pubescent : perigynia 4-5 mm. 



long. 50. C. Davisii. 



XVIII. DEBILES. 

 A single species in our range. 51. C. flexuosa. 



XIX. VlRESCENTES. 



Perigynia densely pubescent. 



Leaves exceeding the culms : lowest bract setaceous, 

 0.5 mm. wide : pistillate spikes oblong-cylindric : 

 perigynia obovoid. 52. C. Swanii. 



