SEDGE FAMILY 191 



Stvle 3-cleft; aehene S-angled. 



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

 Eaehis 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. aristatux. 



Scales obscurely 3-nerved, with short recurved tips 5. C. a'^uminatus. 



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



tall perennial 6. C. virens. 



Rachis with the scales decurrent upon it as narrow searious wings; stamens 3. 

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



Wings persistent on the rachis 7. C. erythrorhiroa. 



Wings readily deciduous S. C. spharelntim. 



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, searious, wholly adnata to rachis; stamens 3. 

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



achenes 10. C. strigo.ws. 



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; involueral bracts 

 2 or .3, foliaeeous, narrowly linear, i/. to Si/o 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; aehene lenticular, sharply beaked. 



Jackson. Hansen 6-i4; lower Sacramento Kiver, Jepson: San Francisco, 

 Bolander 2330; Los Angeles River, Braunton 566; San Bernardino, Parish 

 3811. Mexico south to Argentina. 



Refs.— Cyperus melanostachyus H. B. K. Nov. Gen. & Sp. 1:207 (181.5). C. diandrus 

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

 Club, 13:20.=) (1886). Pyrreiis meJaiiostachi/us C. B. Clarke, Contrib. V. S. Nat. Herb. 10:44(i 

 (1908). 



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

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

 to 4, the longest 4 to 51/. inches long; scales acute, yellow-brown, about 2 lines 

 long, the keel 3-nerved and the margins searious; aehene ovoid, black, Is as 

 long as scale. 



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



Refs.— Cyperus bromoides Link, Jahrb. Berl. 1': 85 (1818); Parish, Bull. S. Cal. Acad. 



Sci. 3:49 (1904). C. uiiiloides R. Br. var. Ijrotiwides 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 l)racts, 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 

 brown blotch on each side, closely imbricated, % line long ; aehene oblong, 

 gray, V-? as long as scale. 



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

 San Bernardino, Parish; Pasadena, McCIatchie : Los Angeles, Brewer. Soutli 

 into Mexico. All continents. 



Refs.— Cypkrus laevigatus L. Mant. 2:179 (1771); Wats. Bot. Cal. 2:214 (1880). 



4. C. aristatus Rottb. Dwarf annual; stems V2 to 6 inches high, barely 

 exceeding the leaves; leaves flat. 1,4 line or less wide; involueral bracts folia- 



