374 CYPERACE.E. (SEDGE FAMILY.) 



2. Spikes one or more : staminate spike always single, usually distinct, sessile 

 or nearly so, sometimes androgynous with all the pistillate flowers borne at its 

 base : pistillate spikes, if any, small and globular, mostly sessile, moi'e or less 

 approximate : bracts short or none, sheathless : perigynium ovate or globular, 

 hirsute (thin and scabrous in No. 4), tightly surrounding the achenium, usually 

 bearing a beak half its length: pistillate scales acute (except in Nos. 4 and 5) : 

 stigmas rarely 2. SPH^RIDIOPHOR^:, Drejer. Low species in dry places, 

 the leaves all radical. No. 5 is dioecious. 



* Spike one, androgynous. FILIFOLIA, Tuckm. 



4. C. filifolia, Nutt. Cespitose: culms slender, obtusely angled and 

 smooth, 3 to 12 inches high, when full grown longer than the filiform rigid 

 leaves, their bases surrounded by dry brown leafless sheaths which at length 

 break up into fibres: spike to 1 inch long, ferruginous or whitish, bractless, 

 the staminate portion sometimes nearly free from the pistillate portion : peri- 

 gynium broadly triangular-obovoid, thin, few-nerved or nerveless, scabrous or 

 slightly hairy above, abruptly contracted into a short, stout, white-hyaline entire 

 beak, about the length or shorter than the very broad hyaline-margined clasping 

 scale: perigynium containing a short serrate racheola, whence the name 

 Uncinia breviseta, Torr. Dry plains and mountains from Colorado westward 

 and northward. 



Var. valida, Olney. Culm very stout, a foot high, rigid, sharply angled, 

 much longer than the long-pointed broader leaves : spike longer, often subtended by 

 a hispid bract: perigynium more glabrous. C. filifolia, var., Boott in Gray's 

 Rocky Mountain Plants, 77. Colorado. 



5. C. SCirpoidea, Michx. Creeping: culms in flower short, elongating 

 (6 to 16 inches high) in fruit and exceeding the broad and flat leaves, more or 

 less scabrous on the angles at least above, the basal sheaths not splitting into 

 fibres : spike ferruginous, linear or club-shaped, | to 2 inches long, occasion- 

 ally with 1 or 2 accessory spikes at base : perigynium ovate or obovate, hairy, 

 lightly nerved, about the length (or a little longer) of the ciliate more or less obtuse 

 scale: scales on the staminate plant hyaline-margined, not ciliate. C. Worm- 

 skioldiana, Hornem. High mountains, Colorado and Utah, northward and 

 westward. (Asia, Norway.) 



* * Spikes two to several, the lower occasionally peduncled or sometimes radical: 

 perigynium contracted below, usually bearing two prominent ribs, the very short 

 or often prolonged beak slightly 2-toothed. MONTANA, Fries (in part). 



<- Culms upright, as long or longer than the leaves: spikes closely flowered, mostly 

 aggregated at the top of the culm. 



6. C. Pennsylvanica, Lam. Extensively creeping: culms few, slender, 

 4 to 10 inches high : staminate spike conspicuous, $ to 1 inch long, often club- 

 shaped, sessile or shortly peduncled, sometimes pistillate at the top : pistillate 

 spikes 1 to 4, the lower one very rarely an inch remote, the upper ones bract- 

 less, the lower sometimes subtended by a short and subulate brown bract: peri- 

 gynium globose or roundish-obovoid, abruptly contracted into a short or often 

 long beak, usually shorter than the acute or cuspidate brown or rarely ivhitish 

 scale. C. leucorum, Willd., is a form with long beaks. Dry sandy plains 

 about Denver (E. L. Greene], Ute Pass, Col. (T. C. Porter); Fort Pierre, 



