CYPERACEAE. 65 



II. CARICES GENUINAE. Stigmata 2 or 3. Spikes mostly unisexual. 



12. MELANANTHAE. 



Spikes several, dense-flowered, mostly peduncled and drooping, contiguous, 

 gynaecandrous or the terminal staminate, the lateral pistillate; bracts con- 

 spicuous, but narrow, sheathless ; scales dark-colored; perigynium sessile, 

 erect, very seldom spreading, sessile, more or less compressed, elliptical, few- 

 nerved, granulated and often scabrous along the upper margins, purplish- 

 spotted to almost black, the beak short, entire to emarginate; stigmata 3. 



Spikes several. 



Terminal spike gynaecandrous or in C. Parryana sometimes pistillate. 

 All spikes gynaecandrous peduncled and often somewhat drooping. 

 Spikes ovate. 



Scales and perigynia blackish. 31. C. atrata. 



Scales and perigynia copper-colored. 32. C. chalciolepis. 



Spikes cylindric ; scales blackish ; perigynia light-green. 



33. C. bella. 



Lateral spikes pistillate, sessile, erect. 

 Spikes contiguous in a dense head. 



Perigynia erect. 29. C. alpina. 



Perigynia spreading. 3- C. melanocephala. 



Spikes somewhat remote, spicate. 



Perigynia subtriquetrous ; lateral spikes usually small or none ; scales 



purplish, with hyaline margins. 34- C. Parryana. 



Perigynia compressed ; lateral spikes not reduced ; scales purplish. 



36. C. Buxbaumii. 

 Terminal spike staminate, the lateral pistillate and peduncled, but erect and 



contiguous. 35- C. Raynoldsii. 



Spike single. 34- C. Parryana. 



13. MlCRORHYNCHAE. 



Spikes several, cylindrical, often dense-flowered, sessile or short peduncled, 

 erect, remote, the terminal staminate, the lateral pistillate or the uppermost 

 staminate or androgynous; bracts foliaceous, sheathless; scales dark, obtuse; 

 perigynia often stipitate, erect, compressed, roundish-ovate to elliptical, more 

 or less prominently nerved, granulated, often scabrous along the upper mar- 

 gins, pale green, the beak mostly minute, entire to emarginate; stigmata 2. 



Perigynia compressed ; beak not bent horizontally. 

 Spikes sessile. 



Perigynia several-nerved ; spikes remote. 



Perigynia stipitate, deciduous ; beak entire. 38. C. vulgaris. 



Perigynia persistent ; beak bidentate. 44. C. nebraskensis. 



Perigynia 2-nerved, not deciduous ; spikes contiguous. 39. C. rigida. 

 Spikes peduncled. 



Spikes short ; scales spreading, acuminate, longer than the scabrous roundish 



perigynia. 40. C. chimaphila. 



Spikes long and cylindric, remote. 



Perigynia rhombic, entirely beakless. 37- C. rhoinboidea. 



Perigynia beaked. 



Perigynia stipitate, oval. . 41. C. acutina. 



Perigynia sessile, obovate to broadly elliptic. 43. C. variabilis. 



Perigynium turgid, with a beak bent horizontally ; spikes sessile or nearly so. 



45. C. scopulorum. 



