WOOTON AND STANDLEY FLORA OF NEW MEXICO. 713 



80. XIMENESIA Cav. 



Annual, more or less canescent, with alternate petiolate toothed leaves and large 

 showy heads of yellow flowers; involucre of spreading linear foliaceous equal bracts; 

 disk and receptacle merely convex; rays numerous, large, bright yellow, usually 

 fertile; achenes flat, obovate, broadly winged, with short setiform awns, the awns 

 not hooked. 



1. Ximenesia exauriculata (Robins. & Greenm.) Rydb. Bull. Torrey Club 33: 

 154. 1906. 



Verbesina encelioides exauriculata Robins. & Greenm. Proc. Amer. Acad. 34: 544. 

 1899. 



Type locality: Kansas. 



Range: Kansas and Colorado to Arizona and western Texas and southward. 



New Mexico: Abundant throughout the State. Fields and low hills, from the 

 Lower Sonoran to the Transition Zone. 



This is one of the commonest plants of New Mexico, being found in abundance 

 almost everywhere except in the highest parts of the mountains and on the driest 

 plains. It is nearly always to be seen in cultivated fields and waste ground. In the 

 northern part of the State, especially in favorable seasons, it covers large areas of 

 ground to the exclusion of almost everything else, presenting a wide unbroken sheet 

 of rich yellow. 



81. WOOTONELLA Standley. 



Low perennial, 20 cm. high or less, with slender deep-seated rootstocks; stems 

 simple or branched, ascending, canescent; lower leaves opposite, the upper alternate, 

 irregularly dentate, narrowed into winged petioles, these mostly dilated and dentate 

 at the base; heads 15 to 20 mm. broad, solitary on naked terminal peduncles; bracts 

 foliaceous, canescent; rays rather pale yellow, conspicuously exceeding the involucre; 

 ray flowers fertile, the disk flowers sterile; palese very narrow, nearly filiform, per- 

 sistent; achenes obovate or oblong, villous, broadly winged, the wings corky-thickened 

 near the apex; pappus none. 



1. Wootonella nana (A. Gray) Standley, Proc. Biol. Soc. Washington 25: 120. 1912. 



Ximenesia encelioides nana A. Gray, PI. Wright. 2: 92. 1853. 



Verbesina nana Robinson, Proc. Amer. Acad. 34: 543. 1899. 



Type locality: "Around the dwellings of Prairie-dogs, between the Limpio and 

 the Rio Grande," Texas. 



Range: Southern New Mexico to western Texas and northeastern Mexico. 



New Mexico: Artesia; Dayton. Plains, in the Lower Sonoran Zone. 



This is said to be a common weed in cultivated fields of the Pecos Valley. 



82. VERBESINA L. Crownbeard. 



Coarse annual or perennial herbs with opposite or alternate, petioled or sessile 

 leaves and few or numerous small or medium-sized heads of yellow flowers; bracts 

 imbricated in 2 or more series, appressed or at least erect, not elongated; receptacle 

 convex to conic; rays several or numerous, large and showy, usually sterile; achenes 

 flat, glabrous or nearly so; awns of the pappus straight, often obsolete or wanting. 



key to tee species. 



Leaves elongated-linear 1. V. longifolia. 



Leaves lanceolate to ovate or oblong. 



Leaves thick, sessile, cordate; heads few, 15 mm. in diameter or 



more 2. V. rothrochii. 



Leaves thin, petioled, narrowed at the base; heads several to 



many, 12 mm. in diameter or less 3. V. oreophila. 



