84 



CYPERACE2E, 



Flowers perfect (the stamens and pistils in the axil of the same bractlet). 



Spikelets flattened, the bractlets arranged in 2 opposite rows 



1. Cyperus. 



Spikelets cylindrical, the bractlets arranged around the axis in several rows. 

 Style enlarged at base, 

 Forming a persistent tubercle jointed on the apex of the achene; spikelet 



solitary, terminal upon a leafless bractless scape . . 2. Elkocharis. 

 Wholly deciduous at maturity; spikelets in an invulucrate umbel 



3. FlMBRISTYLlS. 



Style not enlarged at base, deciduous or only the base persistent 

 Stamens mostly 3; spikelets solitary or clustered or in a compound 



umbel 4. Scirpus. 



Stamens 1 to 3; bristles (perianth-hairs) numerous, long exserted and 



silky in fruit 5. Eriophorum. 



Flowers moncecious or dioecious, usually in separate spikelets; pistil and achene 

 enclosed in an inflated sac-like bractlet (perigynium) . . 6. Carex. 



1. CYPERUS L. Galixgale. 

 Annuals or perennials. Stems triangular, leafy at the base, the 

 inflorescence subtended by 1 or more conspicuous, leafy bracts. 

 Spikelets solitary or clustered on the unequal rays of an umbel with 

 the central spikelet or cluster always sessile, or the whole contrac ted 

 into a dense head. Bractlets concave and more or less carinate, 

 arranged in 2 ranks in a flattened spikelet. Bristles in the flower 

 none. (Kuperos, an old Greek name applied by Herodotus to an 

 aromatic plant used by the Scythians for embalming.) 



Style 2-cleft; achene lenticular; rachilla narrow, not winged .1. C. diandrus 



var. castaneus. 



Style 3-cleft; achene triangular. 

 Rachilla not winged, naked or nearly so. 



Stems % to 6 in. high 2. C. nristatus. 



Stems over 12 in. high 3. C. sei-rulatus. 



Rachilla clothed with the persistent, decurrent wings of the bracilets. 



4. C. eriithrorhizos. 



1. C. diandrus Torr. var. castaneus Torr. Described as an 

 annual with stems | to 2 ft. high, slender, triangular; leaves elongate, 



1 line or less w T ide; involucral bracts 2 to 3, foliaceous; spikelets 

 linear-oblong, acute, 3 to 6 lines long; rachilla not winged; bractlets 

 brown, 1 to 1} lines long; stamens 2 to 3; style 2-cleft to the middle; 

 achene lenticular. 



"Swamps near San Francisco, Bolander, and in the valley of the 

 Sacramento, Pickering. 



2. C. aristatus Rottb. Annual; steins \ to 6 in. high, barely 

 exceeding the leaves; leaves h line or less wide; involucral bracts 

 foliaceous, h to 2 in. long; rays few, \ to 1 in. long; spikelets sessile, 

 densely clustered, H to 3 lines long, flattened; rachilla not winged; 

 bractlets with strongly recurved setaceous tips, striate, chestnut-brown 

 or greenish, 1 line long; style 3-cleft; achene triangular. 



Chico, Greene; Jackson, Hansen; perhaps not occurring within 

 our limits. June. 



3. C. serrulatus Wats. Perennial (?); stems \\ ft. or more high , 

 stout, triangular; involucral bracts 6 to 8, foliaceous, 3 to 18 in. long, 



2 to 3£ lines wide, flat (or conduplicate ?); inflorescence irregularly 

 umbellate, with unequal rays; spikelets numerous, in dense umbels, 



