to 30 bristles, occasionally with a few short and inconspicuous outer setae; achenes 

 asymmetrically 4- to 7-nerved, most commonly 5-nerved. 



Moist meadows, streamsides or bogs in the mts. of N.M. (Rio Arriba Co.), 

 July-Aug.; mts. of Calif., Ut. and n. N. M. 



8. Erigeron formosissimus Greene. 



Fibrous-rooted perennial with a simple or branched caudex; stem 1-4 dm. high, 

 usually curved at the base, glandular at least above, often spreading-hirsute as 

 well; lowermost leaves oblanceolate or spatulate to oval, petiolate or subpetiolate, 

 to 15 cm. long (including the petiole) and 15 mm. wide, persistent; cauline leaves 

 progressively reduced upwards and becoming sessile but usually fairly ample, 

 mostly lanceolate or oblong to ovate; heads 1 to 6, the disk 1-2 cm. wide; 

 involucre 5-8 mm. high, glandular and often hirsute, the phyllaries about equal, 

 the outer mostly 0.7-1 mm. wide; rays usually 75 to 150, 8-15 mm. long and 

 1 mm. wide or a little wider, blue, pink or rarely white; disk corollas 3.5-4.4 mm. 

 long; outer pappus setulose and sometimes very scanty; achenes 2-nerved. 



Moist meadows and wet seepage banks in the mts. of N.M. (Taos, Socorro, 

 Sierra, Grant, Lincoln and Otero cos.) and Ariz. (Coconino, Apache, Navajo, 

 Greenlee, Graham and Gila cos.), July-Sept.; w. S.D., Wyo. and Ut. to N.M. 

 and Ariz, 



14. Conyza L. 



More than 50 species, chiefly tropical and subtropical in both hemispheres. 



1. Conyza Coulteri Gray. 



Annual herb 2-10 dm. tall, rather rigidly erect, sparingly with ascending 

 branches; leaves narrowly obovate or oblong, with a few salient teeth or shallow 

 lobes, apically rounded, basally rounded or usually with auricles and somewhat 

 clasping; heads numerous and crowded in the upper 1-3 dm. in a subpaniculi- 

 form arrangement; heads about 4 mm. high; ray flowers in 2 or 3 peripheral rows; 

 achenes less than 1 mm. long, hispidulous, compressed; pappus a single series of 

 copious dull white capillary bristles about 3 mm. long. Eschenbachia Coulteri 

 (Gray) Rydb. 



Frequent in wettish often alkaline soils, river bottoms, in the Tex. Trans-Pecos, 

 less common in Edwards Plateau and rare in Rio Grande Plains, N. M. (wide- 

 spread) and Ariz. (Coconino to Greenlee, Cochise and Pima cos.), June-Sept.; 

 s.w. U.S. and Mex. 



This plant is known to be toxic to livestock. 



15. Boltonia L'Her. 



Perennial herbs 2-10 dm. tall, essentially glabrous, with taproot plus fibrous 

 root systems and very slender creeping rhizomes (these easily broken off); stems 

 slender, branched, wiry, striate-angled, uppermost parts of the branches pedunculi- 

 form; leaves linear, those of midstem 1-3 (-12) cm. long, green, alternate, entire, 

 essentially sessile, grading upward into leaves as small as 1-3 mm. long; heads 

 small, solitary at the ends of the branches, 5-10 mm. across (excluding rays); 

 receptacle conic or hemispheric, naked; involucres hemispheric, 2-4 mm. high, 

 of about 3 series of slightly imbricated lanceolate appressed phyllaries with pale 

 scarious margins and darker midribs which are slightly expanded toward the apex; 

 ray flowers present, pistillate, fertile; rays white (or pink when dry) or lilac, 

 never yellow; disk flowers numerous, perfect, fertile; corollas yellow, the tube 

 not sharply demarcated from the gradually ampliate shallowly 5-lobed limb; 

 achenes laterally compressed, brown, with 2 wings (or in the ray achenes 3- 



1630 



