90 



CYPERACEiE. 



single) which are commonly aggregated into heads or even panicled; cross- 

 section of the perigynium plano-convex in outline; styles 2; achene lenticu- 

 lar; the spikelets, especially the uppermost, usually have contracted bases 

 when the staminate flowers are borne below the pistillate ones, and empty 

 scales at the top when the staminate flowers are borne above. — Sub-genus 

 Vignejj Koch. 



Flowers often dioecious or nearly so, or the staminate and pistillate flowers 

 irregularly situated, or some of the spikelets occasionally wholly staminate 

 or pisiillate. 



Inflorescence a simple or nearly simple head; perigynium ovate, stipitate, 

 concealed by the bractlet, at length nearly black. 9. C. marcida. 

 Flowers monoecious; spikelets regularly androgynous, the staminate flowers 

 uniformly borne at the top. 

 Spikelets yellow or tawny when mature, short, rarely longer than broad; 

 perigynium mostly small and short and nearly nerveless, or in some 

 species becoming nearly lanceolate and more or less prominently 

 nerved, firm in texture. 

 Inflorescence a simple or nearly simple head .... 10. C. Brongniartii. 

 Spikelets green or nearly so when mature, aggregated or scattered, never in 

 compound heads; perigynium mostly short-ovate, in most cases not 

 conspicuously nerved. 

 Plants slender; spikelets more or less scattered . . . 11. C. muricata 



var. gracilis. 



Flowers monoecious; spikelets regularly androgynous, the staminate flowers 

 uniformly borne at the base. 

 InflorescenVe silvery green or sometimes tawny when mature; spikelets 

 mostly small, distinct; perigynium not wing-margined nor conspicu- 

 ously broadened, mostlv nearly flat on the inner surface. 

 Perigynium ovate, sharp-margined, firm, often thickened at the base, 

 spreading, in open, and at maturity stellate, spikelets 



12. C. echinata. 



Perigynium ovate-lanceolate or nearly linear, mostly in loose spikelets . . 



13. C. Deweyana. 



Inflorescence tawny or dark; spikelets rather large, sometimes crowded; 

 perigynium with a more or less thin or winged margin, which is 

 incurved at maturity, rendering the perigynium concave on the inner 

 surface. 



Perigynium ovate or ovate-orbicular, thickened in the middle 



14. C.festiva. 



1. C. vesicaria L. Rootstock creeping; stems 1 to 3£ ft. high, 

 sharply angled, scabrous; leaves 2 to 3 lines wide, the upper exceeding 

 the stem; bracts exceeding the stem; perigynium conspicuously 

 turgid, ovoid or conical, ascending at maturity, smooth, shining. 



Tomales Bay, Bolander, no. 2303, teste Boott. 



2. C. Pseudo-cyperus L. var. comosa Boott. Stems \\ to 2\ ft. 

 high, stout, sharply angled; leaves rigid, tapering to a long slender 

 triangular apex, 2\ to 5 lines wide; spikelets densely flowered, upper- 

 most staminate; perigynia retrorsely spreading in fruit; beak very 

 long, deeply bifid. 



Swamps near San Francisco, Bolonder, no. 2301, teste Boott; over- 

 flow marshes of flats along Russian River, near Guerneville, Davy. 



3. C. bifida Boott. Stems 2 to 3 ft. high, slender, acutely angled; 

 leaves 1 to 2 lines wide, pale, mostly shorter than the stem; lower 

 sheaths reddish, sparingly reticulate-fibrous; spikelets 4 to 9 lines 

 long, 3 lines wide, densely-flowered, purple and glaucous, the termi- 

 nal rarely bearing a few pistillate flowers above; perigynium shortly 

 beaked. 



Coast Ranges: in rather dry soil, Salinas Valley, Brewer, no. 574; 

 Pacheco Pass, Santa Clara Co., Bolonder, no. 4837, teste Boott. 



