38 POLYGONACEJE. Chorizanthe. 



19. C. Wheeleri, Watson, 1. c. Low with spreading brandies, 3 or 4 inches 

 high, villous-pubescent and tomentose : leaves and bracts tomentose beneath ; the 

 latter oblanceolate, an inch long or less : involucres in small terminal cymes, nearly 

 glabrous, a line long, with short stout teeth, the alternate ones smaller : flowers 

 rose-colored, 1^ lines long, sessile, glabrous, cleft a third of the way down : seg- 

 ments broadly oblong, the alternate ones slightly shorter and broader: stamens 6, 

 near the base. 



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



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

 pubescent, diffusely 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 1| lines long; one tooth with a long 

 straight awn, the rest short and uncinate : flowers nearly sessile, yellowish, glabrous 

 or slightly villous, 1| lines long, shortly cleft: segments very unequal, the outer 

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



At New Idria (Brewer), and at McGinnis' on the headwaters of the Salinas, 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 spatulate 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 : flowers included, 

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

 3 or 6, at the base. Bot. Mex. Bound. 177; Torr. & Gray, 1. c. 196; Watson, 

 Bot. King Exp. 312. 



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



3. Involucres coriaceous, \-Jlowered, triangular or cylindrical, 3-5-toothed or 

 -lobed ; teeth unequal, with straight or curved awns ; tube transversely cor- 

 rugated : flowers included or nearly so, tubular, shortly 6-cleft, glabrous : 

 stamens 6 or 9, with short filaments inserted on the throat. Low, branch- 

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

 2 or 3, distinct : involucres scattered. ACANTHOGONUM, Torr. & Gray. 

 (Acanthogonum, Torr.) 



* Involucres broadly triangular: bracts foliaceous. 



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

 1 to 3 incbes long : leaves 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 : flowers 

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

 very short. 



Collected only on Reservoir Hill, Placerville, by Rattan. 



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

 very shortly branched, usually dense with the conspicuously bracted involucres, 

 the whole plant 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, equal, somewhat villous : stamens 9. 

 Watson, Bot. King Exp. 312. 



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



