;arex 



Cyperaceae 



239 



50 



Map 477 



Carex artitecta Mack. 



50 



Map 478 

 Carex artitecta 

 subtilirostris Hermann 



10-16 mm long, 1.6-2.3 mm wide; pistillate spikes not at all aggregated; 



culms erect 55a. C. artitecta var. subtilirostris. 



Beaks of perigynia 0.5-1 mm long; staminate spike sessile, usually incon- 

 spicuous, 2-8 mm long, 1.5 mm wide; at least the upper pistillate spikes 



closely aggregated or congested; culms weak, more or less arcuate 



56. C. Emmonsii. 



Perigynia inconspicuous in the spikes, largely concealed by the scales, 3-4 mm 



long 57. C. nigromarginata. 



Body of perigynium suborbicular to somewhat obovoid, about as long as wide. 

 Ligule conspicuous, longer than wide; lowest bract truncate or bifid, abruptly 

 awned; leaf blades 2.5-4.5 mm wide; culms generally aphyllopodic, little 



fibrillose at the base, without long, horizontal stolons 58. C. communis. 



Ligule short, much wider than long; lowest bract usually gradually acuminate; 

 leaf blades 2.5 (very rarely 3) mm wide or less; culms generally phyllopodic, 

 conspicuously fibrillose at the base, with long horizontal stolons; staminate 

 spike stout. 



Mature perigynia 1.75-2 mm wide, the body suborbicular in cross section 



59. C. heliophila. 



Mature perigynia about 1.5 mm wide, the body obtusely trigonous in cross 



section 60. C. pennsylvanica. 



Fertile culms of two types, some short (1-5 cm long), partly hidden among the densely 



tufted bases and bearing only pistillate spikes, others elongated (5-11 cm long) 



and bearing staminate spikes only or both staminate and pistillate spikes. 



Leaf blades rather thin, not stiff, erect or ascending, 1.5-3 mm wide; perigynia 



membranaceous, 2.25-4 mm long, the body short-pubescent above. 



Perigynia 2.25-3.25 mm long, 1-1.25 mm wide, the beak about half the length of 



the body; achenes orbicular-obovoid 61. C. umbellata. 



Perigynia 3.25-4 mm long, the beak nearly the length of the body; achenes oblong- 



obovoid, minutely roughened 62. C. rugosperma. 



Leaf blades thick, rigid, widely spreading at maturity, 2-4.5 mm wide; perigynia 

 subcoriaceous, 3.5-4.5 mm long, the body glabrous or very sparsely pubescent 

 above 63. C. tonsa. 



55. Carex artitecta Mack. (Carex varia Muhl., not Lumnitzer nor 

 Host.) Map 477. Common in dry open woods, especially on rocky white 

 oak slopes ; occasional in thickets or low woods. 



Vt. to Iowa, southw. to S. C. and Okla. 



