SEDGE FAMILY 191 



Style 3-cleft; achene 3-angled. 



Sinkelets flattened; scales falling away from the rachis which is persistent on the spike. 

 Bachis naked or nearly so, the scales not decurrent upon it; stamen 1. 

 Scales not toothed on back; low or dwarf annuals. 



Scales 7 to 9-nerved, with strongly recurved setaceous tips 4. C. aristatus. 



Scales obscurely 3-nerved, with short recurved tips 5. C. ayuminatus. 



Scales minutely toothed on back at apex, obtuse or merely acute, without recurved tips; 



tall perennial 6. C. virens. 



Bachis with the scales decurrent upon it as narrow scarious wings; stamens 3. 

 Wings of the rachis soon separating to the base; annual. 



Wings persistent on the rachis 7. C. erythrorhizos. 



Wings readily deciduous 8. C. sphacelatus. 



Wings of the rachis persistent; perennial by means of tuber-bearing rootstocks 



9. C. esculentus. 

 Spikelets not so strongly fattened, deciduous from (but the 2 lowest scales persistent on) 



the spike; wings broad, scarious, wholly adnate to rachis; stamens 3. 

 Perennials with basal tuber-like corms; spikelets falling whole; wings not enclosing 



achenes 10. C. strigosus. 



Annuals; spikelets breaking up into 1-fruited joints; wings very broad, enclosing achenes. 



Spikes oblong, compact 11. C. speciosus. 



Spikes short, loose and spreading 12. C. ferax. 



1. C. melanostachyus H. B. K. Annual ; stems very slender, triangular, % 

 to 1 foot high ; leaves elongate-tapering, 1 line wide or less ; involucral bracts 

 2 or 3, foliaeeous. narrowly linear, !/> to S 1 /^ inches long; spikelets oblong, 3 to 

 6 lines long, in a small capitate cluster; scales chestnut-brown, keeled. 

 3-nerved on back, very obtuse, 1 line long; achene lenticular, sharply beaked. 



Jackson. Hanscn 644; lower Sacramento River, Jepson; San Francisco, 

 Eolandfr 2330: Los Angeles River, Braunton 566; San Bernardino, Parish 

 3811. Mexico south to Argentina. 



Kefs. CYPERUS MELAXOSTACHYUS H. B. K. Nov. Gen. & Sp. 1:207 (1815). C. diandrus 

 Torr. var. castaneus Torr. ; Wats. Bot. Cal. 2:214 (1880); var. capitatus Britton, Bull. Torr. 

 Club, 13:205 (1886). Pycreus melanostachyus C. B. Clarke, Contrib. .U. S. Nat. Herb. 10:446 

 (1908). 



'2. C. bromoides Link. Annual; stems slender, 1 to 1% feet high, exceeding 

 the few rough-margined leaves; spikelets 4 to 9 lines long; involucral leaves 2 

 to 4. the longest 4 to 0^/2 inches long; scales acute, yellow-brown, about 2 lines 

 long, the keel 3-nerved and the margins scarious; achene ovoid, black, l / s as 

 Ions: as scale. 



Los Angeles Co. ace. Parish; Mexico and tropical regions of the Americas. 



Refs. CYPERUS BROMOIDES Link, Jahrb. Berl. 1 s : 85 (1818); Parish, Bull. S. Cal. Acad. 

 Sri. 3:49 (1904). C. uniloides B. Br. var. bromoides Clarke, Jour. Linn. Soc. 21:60 (1884). 



3. C, laevigatus L. Perennial, the stems arising at intervals from a wiry 

 rootstock; stems subterete, slender, 3 to 10 inches high, hardly surpassing the 

 erect filiform leaves ; spikelets 2 to 5, 2 to 4 lines long, in a sessile apparently 

 lateral cluster; involucre of usually 2 bracts, one long (1 to 2 inches) and 

 erect, in continuation of stem, the other short (3 or 4 lines long) or wanting; 

 rachis deeply pitted transversely; scales orbicular, 3-nerved in middle, a 

 l>rown blotch on each side, closely imbricated, % line long; achene oblong. 



y. \'-2 as long as scale. 



Along streams in wet sand : Big Morongo. Colorado Desert, ace. Parish : 

 Bernardino, Parish; Pasadena, McClatchie; Los Angeles, Brewer. South 

 into Mexico. All continents. 



Refs. CYPERUS LAEVIGATUS L. Mant. 2:179 (1771); Wats. Bot. Cal. 2:214 (1880). 



4. C. aristatus Rottb. Dwarf annual; stems y 2 to 6 inches high, barely 

 exceeding the leaves ; leaves flat, a /o line or less wide ; involucral bracts folia- 



