38 



POLYGONACE.K. Chorizunihe. 



19. C. Wheeleri, Watson, 1. c. Low witli sj»re;uliiij,' branclies, [\ or 4 inclies 

 high, villoiis-pubesci'iit and tomentose: leaves ami bracts tonientose beneath; the 

 latter oblanceolate, an inch Ion},' or less : invohieres in small terminal cymes, nearly 

 glabrons, a line long, with short stout teeth, the alternate ones smaller : Uowers 

 rose-colored, \\ lines long, sessile, glabrous, cleft a third of the way down : seg- 

 ments broadly oblong, the alternate ones slightly shorter and broader: stamens (5, 

 near the base. 



Near Santa Barbara, Dr. J. T. Rothrock, on U. S. Geog. Survey uinler Lieut. 0. M. Wheeler. 



20. C. uniaristata, Torr. & Gray, 1. c. Procumbent or ascending, villous- 

 pubescent, ditlusely branching from the base : leaves and bracts spatulate or oblan- 

 ceolate, an inch or two long, the latter diminishing upward and pungent : invo- 

 lucres numerous, scattered, the tube 1 to \\ lines long; one tooth with a long 

 straight awn, the rest short anil uncinate : llowers nearly sessile, yellowish, glabrous 

 or slightly villous, W lines long, shortly cleft: segments very uneijual, the outer 

 obovate, entire, the inner oblong, crenate : stamens 3 or 9, at the base. 



At New Idria {Brewer), and at ilcGinnis" on tlie headwaters of the SaHnas, Palmer. 



21. C. brevicornu, Torrey. Pulverulent or nearly glabrous, branching from 

 the base, erect or ascending, 6 inches high or less, very fragile at the enlarged 

 nodes : leaves broadly spatidate to linear-oblanceolate, an inch or two long : bracts 

 similar, acute or pungent: involucres scattered, narrow, triangular, 1^ to 2 lines 

 long ; teeth very short and hooked, the alternate ones smaller : llowers included, 

 sessile, glabrous, shortly cleft : segments narrowly oblong, nearly eipial : stamens 

 3 or G, at the base. — Lot. JMex. Lound. 177; Torr. -& ^'Vay, 1. c. 19(5; Watson, 

 Lot. King Exp. 312. 



N. W. Nevada to tlie Colorado Valley, Arizona and S. Utah. No well-developed flowers seen. 



§ 3. Involucres conareous, l-Jfowered, trlavgvlar or eylindrlcal, S-5-toofIied or 

 -luhed ; teetli vneijual, with stniiij/it or curved awns ; tube transverseli/ cor- 

 vxigateil : Jlowers included or nearly so, tnhulnr, shortly Gn-left, ylahrous : 

 stamens 6 or 0, with short flaments inserted on the throat. Low, branch- 

 ing and fruiting from the base, villous-jnibescent and tomentose: bracts 

 2 or 3, di.stinct: involucres scattered. — Acanthogonum, Torr. (t Gray. 

 (Acanthogonum, Torr.) 



* Involucres broadly triangular: bracts foliaceous. 



22. C. polygonoides, Torr. & Gray, 1. c. Decumbent, villous-puhescent : stems 

 1 to 3 inches long : l.-aves and bracts narrowly oblanceolate, an inch long or less, 

 acute ; floral bracts very short : involucres rather crowded on the short branches, 

 broadly triangular-turbinate, 3-costate, with 3 stout and broad divergent uncinate 

 teeth longer than the (1 line long) tube ; the intermediate teeth very small : llowers 

 nearly sessile, slightly exserted : segments oblong, equal : stamens 6 or 9; filaments 

 very short. 



Collected only on Keservoir Hill, Plaecrville, by lUitUin. 



23. C. rigida, Torr. Sl Gray, 1. c. Erect, 1 to 4 inches high, villous-pubescent, 

 very shortly branched, usually dense with the conspicuously ])racted involucres, 

 the whole jilant becoming rigid and persistent : leaves ovate, 3 to 12 lines in diam- 

 eter, on long petioles, tomentose beneath : bracts similar, obtuse or apiculate ; floral 

 bracts linear-subulate, stout and spinescent, 6 to 15 lines long: involucres with a 

 broad-triangular 6-costate tomentose tube, a line long ; teeth 3, unequal, lanceolate 

 and carinate, spinescent or pungent, 2 to 9 lines long : flowers yellowish, nearly 

 sessile, equalling the tube : segments oblong, ecpial, somewhat villous : stamens 9. 

 • — "Watson, Lot. King Exp. 312. 



From Northwestern Nevada to the Colorado Valley, Arizona and Southern Utah. 



